Art - Just do a drawing every single day and that's 365 drawings in a year. That's exactly what I did, and believe it or not I got an A* in GCSE lol. Anyhow Art is so fun in A level, i even consider it a free period because I draw in my spare time anyway.
Maths - I'm doing maths, I got A* GCSE but it's really hard in A level. So it does require a hell of a lot of effort. Unless you're really good at it anyway that is...
Photography - Like VirginMary said, you don't need an a level to take good photos.
Media - it's seen as a complete doss by a lot of Universities, but I don't do it so I don't know.
History - If you're interested and are able to do weekly essays then yes take it. I would have but i can't handle all the essays
Psychology - Also pretty hard but it's seen as a good A level I think.