Good morning! In my campaign I have a level 7 Genielock Thri Kreen.

HSC is my strat where Horobak casts slow on the enemy, then my familiar Yusiful (Who is a sprite) casts Summon aberration (The large Slaad Cluckington), Cluckington then flanks the enemy whilst they are slowed. At level 7 is there any improvements i can make?

How is your familiar casting Summon Aberration? This is not possible with the basic rules.

Try to convince the DM to give everyone in the group some really cool magical items. The tomes that increase your stats are fantastic, make sure you all get one of each. Also, try to make it so that the enemy doesn't hit you with their attacks by using cover and having good AC. If you do get hit, have the clerics or druids in the party heal the PC that got hit. Also, you have to wait until level 8 to do this though, when you get an ASI or a feat, choose a feat that is beneficial to your character or raise an ability that you don't think is high enough. Those are some fantastic improvements. B)

Actually it is my friend! If i give the familiar my ring of spell storing he can use it to cast the one spell in it

By basic rules, I meant the basic rules for familiars. Any talk of strategy depends on how you are achieving it currently.

You might be better served by putting Slow into the Spellstoring ring, as that would give the Sprite 1 more spell level to cast during combat.

If you can also get a Master's Amulet, then you can also have a flanking fighter join the Slaad.

Yes, that is what i've done as of late. I also ask, whats a master's amulet?

Oh my literal tarrasque. WHAT IN THE NAME OF RAVEN QUEEN IS THIS ITEM?

Update to the strategy: 

Horo casts summon aberration, then yusiful slows the opponent, then the shield guardian casts summon abberation. 

The Cluckington Cluckington Shield combo! 

Good gods, you could even give him something like a water weird tank, have him carry something like that around to have another summon

This 4'9 Thri Kreen is a god dang menace 

There are a few loopholes for getting gobs of minions if you want to, just be mindful of how bogging down action economy negatively impacts party fun.

In a 3.5e room/puzzle clearing competition, we were given a sizeable chunk of gold to spend on equipment and magical items. I spent all of mine on something like 12 homunculus and high level magic potions. It was fun for me, but totally undermined the event.

That's completely fair, I can see that dragging the fun meter down a bunch. I'll just stick to the Guardian and my 2 summons. Unless a tarrasque pops up! Than the Waters coming out!