Definitely play fewer hands. I think that's a big problem with beginning players.

I've also seen a lot of new players who are afraid that they're always being bluffed off of a hand. They don't want to look foolish, so they'll call things all the way down with nothing, just so they don't have to fold. Incidentally, that tends to make you look foolish.

I think one of the best things I was told when I first started playing was that I need to remember that I'm not the hero. This isn't a movie and I can't just expect to draw the miracle card in the very end and win a bajillion dollars. It doesn't work like that.