You can take two completely unrelated words that you like and put them together. Like, my sister on dA is BudgieContraption which I first misread as BudgieContraception (which is much better, lol). Or you could make a list of your favorite things (color, animal, food, TV show, movie, song, song lyric, random word, etc.) and combine them in a creative way. Like, I might do "bluechocolatechicken" because it describes stuff I like. My URL is fishsticksandpudding at the moment, a reference to Doctor Who. Just think about something you like or something that means a lot to you and fool around with it.