Learn how to edit brush settings, practice smudging, learn what colors compliment each other best. Try not to crowd your sigs with effects ( a simple effect used right > a bunch of snazzy ones used wrong)
Don't even touch bevel / emboss ever again for borders. (or outer / inner glow.. or any other shortcuts)
Download some c4d packs from sites like deviantART: where ART meets application! and Planet Renders v4
Read tutorials (like the ones found in OUR tutorial section) and just try and grasp the basics.