The Basics
1) All potions start off with nether wart to make awkward potion except for weakness potion
2) Redstone added to any potion makes it last longer
3) Glowstone added to any potion makes it II f.e. Instant Damage II
4)Gunpowder added to any potion makes it splash potion
Positive potions
Fire resistance: Magma Cream + Awkward potion
Health: Glistering Melon + Awkward potion
Regen: Ghast tear + Awkward potion
Strength: Blaze Powder + Awkward potion
Swiftness: Sugar + Awkward potion
Night vision: Golden carrot + Awkward potion
Invisible: Night vision + golden carrot
Negative potions
Poison: Spider eye + awkward potion
Slowness: Fermented spider eye + Potion of swiftness
Weakness: Fermented spider eye + Bottle of water (NO AWKWARD POTION)
Instant damage: Fermented spider eye + Potion of Poison