Step 1: Create another human, preferrably female, with similar immortality for purposes of companionship.
Step 2: Create two non-human companions for myself. One in the form of a ghostly, most likely serpentine dragon, the other in the form of a cute, vaguely spherical frog [http://media.tumblr.com/tumblr_m800beQG5I1qg9pym.png].
Step 3: Create a few more immortal humans based on friends of mine to help me out with this whole omnipotence thing and keep me company.
Step 4: Create a few mini-worlds/galaxies/universes/whatever, some to get the hang of this, others based on things I like as sort of a way to keep myself and my companions entertained.
Step 5: I'd design a few worlds with intelligent life, and the laws that the universe follows. I guess I'll go with the idea of a couple of species on a planet, with a few species whose planets are near each other.
Step 6: I'd help the intelligent life forms until they reach a point where I'm confident that they can survive on their own. I'd encourage morality based around thinking out decisions logically, and on the consequences of their actions. The only rules I would provide them would be standards of cleanliness, and rule number one will state that once a rule no longer serves a practical purpose in ensuring the continued survival of the species, you can throw the rule away. The only moral rules will be 1) War in the name of myself or my companions are forbidden. Even if Brian says it's okay, don't do it. 2) Freedom is the right of all sentient beings. Basically, two simple moral rules, an encouragement to think decisions out rationally, and a standard of cleanliness similar to the Kosher laws, but with the instruction that, as soon as you reach the point where you can safely disobey a rule, you are free to ditch the rule.
Step 7: Create an afterlife. I'd go with the idea of a choice of afterlives based on what you want it to be life, with the only thing determining your position is whether or not you managed to live up to some basic moral and ethical standards (Whether you actually considered consequences or just said "ah, who cares"), and whether you followed the two roles. If you were a total douchebag, you'd be reincarnated, and have to try it again. Each time you die, you are told of your previous lives. If you broke one of the only two moral rules, are given one more chance. If you fail that, you cease to exist.
So, yeah, a bit of my own ideas and a bit of the ideas of others. Your thoughts?