First impressions are a must. That's why you should study everything in this guide before pulling your first caper. I know you might get bored waiting, but if there's anything that working in food service taught me before I made it big (ha ha), it's that presentation is half the meal.
Alright, down to business!
First, pick a major city, but not too major. Everyone goes to New York or Los Angeles. Don't be that guy. Those places are saturated. You want somewhere with a lot of opportunity for crime, but not a huge installed base of competitors. Heroes may go easy on you, but the established villains know the score and will not hesitate to rub out small fry that muscle onto their turf. Worse, you could get taken over by a big-name player and made into a lieutenant or something. This is absolutely the worst thing that can happen! You're going to live for the rest of your life - and that's a long time - in someone else's shadow. You don't want that, do you?
Second, try your best to latch onto an existing superhero, preferably a nice, civic-minded do-gooder. You want someone who'll escort you in handcuffs onto the paddy wagon, not rip your head off with his bare hands. Yes, capture and imprisonment is always a possibility, so plan for it! Don't get cocky.
The absolute best villains, the one who show they've got brains and creativity, are the ones who can make their chosen hero seem like the person who led to their empowerment. If you can fabricate a backstory that makes Captain Shinyass look responsible for your creation, other heroes will generally leave you to him to take care of. Nobody likes cleaning up someone else's mess. That's good, because you want to work with a known quantity instead of facing every hero in your city.
Third, get yourself a safe-house. This is not your lair. You don't bring kidnapped reporters here. You don't build your bombs here. You don't do anything here except live. When everything goes south, this is where you go to rest up, figure out what went wrong, and plan for the future. Lairs blow up or burn down. Hidden headquarters get filled with water or concrete. The cops dismantle floating fortresses. Your safe-house shouldn't be any of these things.
Fourth, come up with a few stock capers you can easily pull off with your powers. These are your go-to sources of fun (or funds) when you can't be more creative. Everyone hits dry spells. Everyone runs into a wall coming up with new ideas for villainy. That's fine! Don't let those get you down. Just go back to your stock capers list and pull off one of those. A successful crime does wonders for your confidence level.