It's definitely not illegal as long as your work is 100% original, and you're not using anyone else's art.Ok so i understand selling this stuff is against the law since im using somebody eleses work or something like that, well what other things could i do to make some cash in Photoshop? Website Design? Banners?
As for other options - website and banner design is always possible if you have the skills. Have you ever done anything like it? Both will require clients, however - and with the very tough competition on the web design market, it'll take time to build up something. Contacts is necessary. It does pay a lot of money if you know what you're doing, though.
