So you don't want to ruin your table with water stains, but those nice coaster you've seen are a bit above your budget. But what about the cheap cork coasters? Yeah I hear you thinking, ugly and boring... So why not pimp them?
What you need:
6 Cork Coasters (Kmart $2)
Sharpie(s); Metalic, White, or Black
Directions: GET CREATIVE!! But try to keep it to simple patterns, since you don't want to make it too busy. ENJOY! Photo from fellowfellow.com