Alchemy & Enchant. The most powerful skills/perk trees in the entire game. Combined they can make it game breaking.
Alchemy: Take the first perk all 5 times, then take the next perk which branches off after that. Now go up the right branch 1 perk. All the upper perks are crap. I like poisoner, but it doesn't sound like you need it.
Total it is 7 perks. Now it only beefs up enchant a little compared to store bought potions. Best store bought potion: raises enchant 25%, the ones you can make with alchemy enchanted gear are around 30% so not a huge bump. But it boosts smithing a LOT. I think the best smithing potion is 50% increase. I'm currently making 100% increase smithing potions and I still don't have alchemy and enchant maxed with all perks.