To make a Potion of Regeneration (1hp/2.5s;0:45), you first need to make an awkward potion
after the awkward potion is finished put a ghast tear in the top slot and wait for the Regeneration potion to finish
For the Regeneration II effect (1hp/1.2s;0:22), put a piece of glowstone dust in the top slot and the potion of regeneration (0:45) in the bottom slot
For a longer lasting effect (1hp/2.5s;1:30), put a piece of redstone in the top slot and the Regeneration potion (0:45) in the bottom slot
If you want to make a splash Potion out of it you simply put a piece of gunpowder in the top slot
And if the splash potion is not enough for you and you want to make a lingering potion from it, then you just put a bottle of dragon´s breath in the top slot and the splash potion in the bottom slot
