Never buy paint based on the paper samples at the home improvement store. You should always buy a tester/sample and paint directly on your surface at home. The paint will look different based on the conditions of the environment (fluorescent lighting at the home improvement store vs. natural light at your house, etc). If you are going to paint a wall, don't spend hours looking at the paint sample on a horizontal surface. The color will look different on the wall than it does on a table or countertop because of the way the light in your home hits the surface of the sample.
PAINT STIR STICKS
After the hours spent testing colors and hours spent painting your project, don't throw out your hard work, I mean, stir stick! Your used free stir stick can be a valuable investment. Simply transfer the information from your paint can label. Don't forget to include the room or project the paint was used on. The paint stick can be a useful tool for taking to the paint store for an additional can of paint or to be used as a color sample when out shopping. I much prefer to see the actual paint on the stir stick rather than the paper color sample.
TOUCH UP PAINT
If I have to run out to the garage and dig through shelves, I'm less likely to do touch ups. Keep touch up paint easily accessible somewhere in your house. I keep touch up paint for my kitchen cabinets right in my kitchen. Touch up paint for other rooms is stored in a hall closet. I simply use old jars or tightly sealing plastic containers for my paint.
I prefer the green Frog Tape over the traditional blue tape. It makes a much tighter bond that paint rarely seeps through. I run a very thin layer of paint on my taped off area (almost no paint on the brush) and let it dry for a few minutes before coming back with more paint. This allows for the paint to create a "seal" to prevent the second layer of paint from seeping under the tape. *Please note, this usually works great, but not always!
IT'S JUST PAINT.
Don't be afraid to try something new or different. If you don't like it you can always PAINT over it again. What colors make you happy or relaxed? The paint in your house should tell a story about you.