The first step to becoming an Evil Genius is first to verify that you are a genius and not just some mouth-breather who thinks they are a genius. There are many different IQ tests available on the internet, but to save you some time just ask yourself if you find this blog amusing. If you do then you are probably a genius and more than likely incredibly handsome.
Once you've determined your geniusness , the next step is to pick the group or person you will be exacting revenge on. Because unless you can say "[Nemeses] laughed at me when I was at [location where you were laughed at for your forward thinking ideas that seemed ludicrous to everyone else even though everyone should have figured out by now the advantages of owning an artificially intelligent vibrator], but I'll show them! I'll show them all!" you really aren't giving people sufficient reason to be terrified of you and your impending evilness. Remember, without scary monologues, evil geniuses are just that smart kid you beat up all the time in high school, because maybe he couldn't climb all the way to the top of the rope in gym, so you pantsed him, and I still have nightmares about the way Jenna Fishbaum laughed at my penis.** On a side note,You need to have a way to make lightning flash when you say the "I'll show them all." part, both for dramatic purposes and because summoning lightning is like, Evil Genius 101.
I should like to point out that it is not necessary to have actually been at the place where you were laughed at or to even positively identify those you are accusing of laughing at you. For instance, I always say "They laughed at me at Harvard, but I'll show them! I'll show them all!!", despite the fact that a) I have never been to Harvard. b) I don't know anyone who HAS been to Harvard and c) I can't think of any reason why the people at Harvard would laugh at me. I'm just going to go ahead and assume they WOULD HAVE laughed at me and exact my revenge like they did. It strains credibility to say "They laughed at me at the Massapequa Junior Nail Technician College but I'll show them! I'll show them all!!" because who gets that worked up about nails to begin with and so what if I painted that lady's toes lavender when she asked for purple. It's the same effing color, you jerks.
Next phase: Hiring Your Thugs!!
* Knowing how to spell "vengeance" without having to look it up is a sure-fire way to determine that you are an evil genius. I know because I JUST DID THAT. I think we can all agree that I'm amazing.
** Hattori Hanzo assures me Jenna was laughing out of terror at its sheer girth, because laughter is one way to really tell that someone is terrified, but I think he's just saying this so I stop wetting the bed, which is awfully nice of him.