Any people you want to be enemies with?
I have a few enemies here. Tangy Citrical Fruit, Fiesty Vixen of Desire, Periwinkle Tulip Princess, and Dangerous Horsey Lady are my enemies I declare war with.
To make someone your enemy you should do something heinous, like killing their family, causing their misfortune, or kick their puppy. That will help you make enemies with anyone you want.
Then you can start the plotting. How will you destroy your enemy before they destroy you? You can hire henchmen to do your dirty deeds if you don't want to get your hands dirty, but maybe you want to make sure the job gets done properly.
Then once your enemy is vanquished, you are victorious! You are a full fledged villain! Come to the dark side or something.