Do you play a real instrument? If not, then learning a bit of basic guitar or piano is a great thing to do as it's really handy to play about with chord progressions. Also when you download other peoples tunes, don't just listen to them in a player, use a tracker and when you hear a bit that's really cool and you want to know how they did it you can usually press a shortcut key (such as 'g' in impulse/schism tracker) to jump to that point of the pattern. Step through the pattern line by line, see and listen to how they're using effects, offsets, etc, to make the most of their instruments. See how they use percussion not just to add a beat, but to bring variety to a song (this is usually a great failing of mine, I often copy and paste percussion pattern to pattern which is lazy and not very interesting). Also spend time playing with instrument settings, pitch shifts, sustains, fades, filters, etc. A good understanding of how these settings effect how a sample sounds will put you in a good position when entering compo's online with set sample packs. Tracking is no different to playing an instrument- spend 10 minutes a week and you'll hardly improve, spend an hour a day and you'll be tracking like a pro in no time! Have fun!