Hello! Wanted to get some tips from fellow dungeon masters on how to make your world feel more alive! I’ve been working on my homebrew world for about a year now, and I somewhat feel as if I’m not making it feel alive, or that it might be somewhat annoying or taxing on my players, my tips will help!

I can help with "alive."  "interesting" or "fun" are kind of in the eye of the beholder.

Let me start (and I don't know if you need to hear this or not) with a quick warning.  One of the things that "annoys or taxes" players is if a DM gets to feeling insecure and thirsty and overcorrects by dumping huge amounts of world-building lore and exposition on them.

"Real" is a function of the senses.  You want to appeal to the players' senses; using language that helps them imagine geography, sight, sound, smell, etc.

"Alive" is a bit trickier.  Alive is giving the players the sense that there are more stories going on in this world than just theirs.  You don't want to tell these stories, you just want to show the players that they're there in the background.  In The Lord of the Rings, the hobbits fall asleep under an evil tree and meet Tom Bombadil.  Then they leave and never see him again and he has nothing whatever to do with anything.  But this interlude does give you a sense that there is more than just this one saga going on in Middle-Earth.  

In a movie, you can tell these stories visually, with sets and costumes.  So there's a horse motif on all of the armor in Rohan and a tree motif on all of the armor in Gondor.  In a D&D game, it mostly has to come from you, although your players can help.  You can add art or props if you have the time and the inclination.  They don't have to be anything complicated: a menu, a letter, a map.  But your main tool is still descriptive language.

Referring to current events elsewhere in the world, lore, history, descriptions of architecture or costuming, the swear words people use, their accents, if any, the food they eat.  If they're trying to cross town to visit a wizard's home, telling them it takes longer than usual because of a snarl of wagon traffic at a city watch checkpoint.  Watching a group of little kids chasing a cat around in a place where you don't speak the language.  Birds picking through horse poop for undigested oats.  Hearing the shouts of street vendors.  Seeing a new kind of flower in the forest that you've never seen before.  Something as simple as a coffee ring on a table or graffiti on a wall tells you that you live in a world that's alive.  Just give an impressionistic little detail here or there.

I also said that the players could help.  If they have backstories, have them share those details with each other.  That's x number of different places and people and quests and stories right there!  Empower them to tell you about the part of the world they come from and then work those little details in.  If one player does a Russian accent, tell them there's a neighborhood in the city that has a lot of their countryfolk and a public bath where someone will hit you with willow branches as a form of massage.

The key is probably not to do too much of it.  If your players are scared to ask about the significance of a piece of art you describe because they know the follow-up lore dump will derail the whole evening, they just won't ask.  And then you'll wonder if they're just not engaging because the world doesn't feel alive enough and start doing the lore dump anyway.  You let the work you put into world-building become a kind of intangible DMPC, hogging their spotlight.  So, just a little dab, once or twice per location change, is my advice.

I have always found that the incidentals provide depth and a "lived in" feel.

The beggar that the party encounters as they enter the city who begs for food or coin. The street hawker selling tarts. The suspicious, or lazy, town guard. The weather, The barmaid. the things that just happen all around the players that are not connected with the current quest, job, or adventure. these things combined with answers about local happenings, politics, rivalries, history, etc combine to let the players know that the world goes on without them and there is far more to see or do than they'll accomplish.

Don't be a tour guide though. let things happen and have answers ready when they ask or investigate. keep a list of NPC names & places for future visits and continuity (though you can let them have to remember names and places on their own). let the players develop casual or working relationships with them (good or bad). Perhaps on a future visit the beggar is gone and the players want to know why....

I have rather in depth backstories and histories going back literally 1,500+ years...mostly in my head since I lost my old maps and write-ups. I am in the process of recreating the world after a long hiatus...hence much of the time passing.

My current group (my mostly grown kids) started out as hired guards for a caravan that got raided near the border with another kingdom. they ended up taking on a bandit gang and freeing a group of Dwarven merchants who had been enslaved. As a result they have the gratitude of the Guild as well as the specific Dwarves they rescued (Shh...we don't talk about the one they accidentally killed). Now they carry tokens that can get them information or good prices from other guild members throughout the kingdoms. They have used the tokens once or twice.

Now they have begun to settle down and build/protect a town. Their guild connection gained them favorable status and a ready pool of Dwarves, and guild associates interested in the venture and possible profits. A mine was discovered and now helps bankroll the town and make the players "respectable".

All this, except the rescuing part, was not and is not part of the overall campaign just a development that helps to invest them in the world and game. The main goal and "baddie" is yet to be revealed....

For "alive," I think you need a couple of things. (1) The characters should be able to cause permanent and lasting changes that have repercussions outside the immediate scope of the adventure. And (2) events need to occur outside the ambit of the PCs, and be brought to the attention of the PCs in some way (rumors, news, etc.) so they know about them. Let's look at both of these in some detail.

1. PC actions cause permanent change. If the PCs do something like clean out a goblin lair, then there should be some resulting change to the immediate landscape. Did they clean it out and just leave it abandoned? That might lead to something else (something worse?) moving in -- nature, after all, abhors a vacuum.  Did they clean it out and then tell the local army about it? Maybe the army went and posted guards, and now the area is safer than before. Maybe it's being used as a local mine now, and the town is wealthier, having more to sell the next time the players come back. Or for instance, in my campaign, the players found out that the local mayor had betrayed the Empire, and got him deposed and replaced by the local Centurion, who was friendly to them and gave them more quests. They felt they could contact her and get advice from her later on - so they had a local politician on their side. This lasted well after the adventure in which they discovered the betrayal of the first mayor. That former Centurion is STILL the head of that town. If they go back, she will be there. By having these long-lasting changes exist in response to player character actions, the deeds of characters become more real, and don't feel transient. This gives the world an enduring feel, and a permanence, which makes it feel more alive.

2. Things happening outside the PCs' ambit. In a living world, things are not static. Unlike a computer game, in which nearly everything is set to happen on a trigger of the player entering a particular zone or map area, a real world has things going on all the time. If the players spend 2 weeks in a dungeon over here, a mad wizard might be conquering another town over there. Countries may be conquered. Cities may fall. Assassins may strike. Old friends might disappear because they were kidnapped by the thieves' guild that the players decided NOT to deal with last session. And so on. As an example, in my game, the Roman Empire is being attacked by a mysterious and powerful enemy force. While the PCs were investigating the last city to be hit by this force, another city was hit. On the way home, they contacted the Cleric's uncle, who had been traveling near the new target, and he told them this new city had fallen. So, things were going on while the PCs were otherwise engaged. Having events occur outside the immediate ambit of the PCs (and outside their ability to affect those events), helps the world feel like it is in motion, rather than static. This makes the world feel more alive.

I think if you do these 2 things -- make sure that player actions have lasting consequences when the situation calls for it, and make sure that events are going on outside the ambit of the PCs -- the world will definitely feel more alive.

Look to the way some video games handle environmental story telling, think about what they do to immerse the players in the world - especially stuff not related to plot.

Show don’t tell

i like to create things that exist in the world for my players to engage with - diaries of people in the world, children’s stories, invitations to important events, letters between people, historical reports etc. Not as something I read out but I put them in the discord server for them to engage with.