Don't use ROYGBIV as an organizing tool
It's really more of a styling method and most of the time it is more functional to organize by category or use. Do you really want to go hunting for the blue box of pasta or the yellow board game because you're locked in to a color-coded system? Exceptions: small book collections, categorized clothing.
Don't buy any organizing products before measuring your space
Be intentional about your purchases, even if you find bins on sale at your home goods store and you want to try and stock up. Assess the space, figure out how you want to use it, and then measure carefully (length, width AND height).
Organize by function in a way that makes it easier to find things and put them away without having to think about it too much.
Don't rush the process
Take your time. If you go through your space slowly and thoughtfully, it will create a lasting transformation that you will not have to keep going back to redo.
Don't organize your junk
Go through a good round or two of decluttering first or else you will be rearranging a lot of stuff you don't need
Don’t use labels like “other” and “misc”
If you’re going to take the trouble to organize your stuff, put it in bins and label it, use designations that will actually help you find things when you need them. A miscellaneous bin is just going to turn into a big black hole that will need to be organized all over again. Try using labels that are specific enough to be useful but not so general that it defeats the whole purpose of dividing things up.