I am hooked on the small 'try-it-first' cans of paint that are now widely available. I first purchased one of these last summer from Restoration Hardware and have since used the little cans to try lots of fun colors. The latest is 'New Grass Green' from Glidden and I'm trying it on the shelves in my laundry room. It's such a great color that I'm sure I'll end up buying a whole gallon, but it's hard to commit to a vivid color without seeing it in the room first - especially when you're surrounded by hundreds of paint chips.
If the color doesn't work for your original project, it can always be used for craft projects. Another great paint deal is to look for pre-mixed colors that were rejected for some reason. Most home stores have a shelf of these in a variety of finishes. So, if you're not set on a specific color, you may pick up a great paint at a bargain price. Must run now . . . have to try my new paint!