I'm pretty proficient in Photoshop. A couple of my gamer friends have asked me to design abstract/dark/gaming signatures and avatars, and I've done all of them within 24 hours. They've been very happy with it so it's good.
The thing about Photoshop - You have to keep at it. Messing around once in a while, I think, will not increase your skill levels enough to be able to use it properly. And i also HIGHLY recommend buying a book. I recently bought 'How to Cheat in Photoshop CS3' by Steve someone or other and he is an expert who knows his stuff. He writes clearly and provides step by step detail so even a newbie could follow. I'm moving on to try and design banners. I'm offering free design right now in an attempt to promote my own forums and improve my skills
I've got time on my hands. I gotta use it while I can!