Curious to get the collective wisdom of fellow DMs on this one.

One of my players has a 3rd level Wood Elf Gloom Stalker Ranger. 

On the party's current outing, they've ventured into some heavy forest. In our last session, as the party moved through the wilderness, this player took some time to gather materials he could use to create improvised camouflage to improve his chances at stealth.

Without a specific mechanic in place for this kind of low-level improvised camo, I'm wondering how I might go about rewarding his ingenuity without overpowering him.

I'm thinking I'd require a crafting check with no proficiency bonus (since he's not proficient with weaver's tools) to create the improvised camo. Say it takes... 8 hours without the proper tools? If he succeeds, I'd give him a bump on stealth checks (advantage seems too much, but maybe +2?)... and in battle, I'd allow him to take a hide action without cover if he's in terrain that matches his camo.

Then, at the end of each encounter, or each day, I'd roll to see if the camo fell apart and needs repair.

What do you folks think about that balance?

What is improvised camouflage? You mean like something to make a fake bush or something he could hide behind? Or attaching stuff to his clothes so he hides better?

If that’s the case, I’d say some kind of tool proficiency to make it would work. Personally, I’d give advantage, but it’s only really going to work while in that particular forest. Otherwise, it will look out of place and draw attention more than it serves for hiding. And I’d only let it work once, or maybe for day. Partly because, before long, the plants will start to die and thing will fall apart. Partly because it’s essentially crafting an item, and you don’t want to give him permanent stealth buff because he got some sticks. If it was that easy, everyone would do it. It’s good to reward the creativity, but there’s got to be limits. 

Yeah, attaching stuff to his clothes so he hides better.

Sounds like your thoughts were more or less in line with mine. Thanks!

Honestly, I would just call this taking extra time. Improvised camouflage is something people just do if they're trying to be sneaky and have the time to do it, though it is primarily useful when not moving.

What you’re talking about is really what the “hide in plain sight” ranger feature was supposed to do. Prepped in advanced and usable into a single combat then has to be prepped again. I would treat it exactly like hide in plain sight.

Improvised camouflage could grant advantage to the Dexterity (Stealth) check or disadvantage to the Wisdom (Perception) check if you want. but like Wi1dBi11 said it's very similar to the feature Hide in Plain Sight so i would be careful with this and only allow the benefit sparringly as the comparable is a level 10 feature.

I rule that if you are not doing this then your stealth rolls are at disadvantage (trying to do a task with improvised or no tools).

Being stealthy includes using the enviroment around you.

Thanks everybody! This makes a ton of sense. I'd totally forgotten about the "Hide in Plain Sight" feature. That puts a lot of this in context.

I would say that attaching branches and such to your clothes would have a few effects:

1: You have advantage in stealth (and others have disadvantage in trying to see you) when the enemy are over 30ft. away and you're in your chosen cover and not moving.
2: You have disadvantage on steath (and creatures have advantage on trying to hear you) if you are moving, or in contrasting terrain.

I nreality, guilly suits work because people wear them and stay still. moving around in one is noiser than normal clothes (all that rustling) and doesn't help you blend in at all.

I'd have it need remaking over a short rest or long rest each day, as it will quickly wilt and die.

like ThorukDuckSlayer said

what about let him make some kind of ghillie suit. but only for the environment where the material was found.

while in an other environment ghillie's dont work.
the movement is still very viable as stealth. i know an airsoft guy who moved about 35 meters towards me and i never saw or heard him.

instead of giving a disadvantage i would go for half movement(walk,climb ect.) when he uses the suit.

and give him  advantage when he uses a ranged weapon that barely  makes a sound(bow's and blowpipe)

but he is instantly seen if he uses a ranged weapon that makes a sound(crossbow's and guns)

Crossbows aren't any noisier than longbows.  Which aren't silent.

At 100+ yds they can’t be heard 😁