How to pick colors for your home:

1
Think combinations, not colors.
Picking colors is in fact about picking a combination of colors. One color is no color. Did you know the human eye can't even perceive single colors? We can only see color differences, in other words: we only perceive contrasts. Therefor it's no use fretting over a single color for your walls. Because the million dollar question is: how does that wall color relate to the existing color of your floor.

2
Start with the colors you can't change.
Obviously, a palette is made up of different colors that need to fit together. If you want to paint your room and you have colors you cannot change, like flooring, curtains or furniture, they still need to be part of the palette. Therefor always keep them in mind when picking the rest of the colors. As a rule of thumb, you start with the colors with the smallest range and work towards the widest range. For instance: look at your existing flooring and furniture first, then pick the new curtains, and finish with the wall color.

3
Get inspired.
There are many ways to get inspired. You can search the web. You can pick a flower and match its colors to a paint fan deck. You can take any picture or painting you like and extract colors from it. It's really not that hard. Just pick something that inspires you and match it to paint colors to produce a great palette. A few hints to keep in mind when making a palette:
• Try to include light as well as dark colors. Remember: contrasts are key.
• If you go for greys, pick at least one bright color to accentuate.
• If you go for bright colors, combine it with at least one shade of grey to provide your palette with a neutral tone.

4
Visualize
Once you established at least some idea of a palette and a rough idea of what it should look like, you can start experimenting, using Colorjive (for now, only here). Just try out different ideas. Don't be shy, you can change colors in an instant. Once you know your wall should be blue for instance, you can try different shades of blue till you find the one that works for you.
You can use the software to show the result to your friends and family. After all, they'll have to put up with it.

5
Check your choice
When you use the color codes to order paint in the shop, first take a good look at the color swatch to make sure this is the color you want. Colors onscreen may differ from real life colors. If you are still a bit uncertain, buy a sample or a small pot of paint first. Then paint a small surface to see if it works. And remember: it's only paint. Worst case scenario is repainting. So you can afford to take some chances.