Since I generally build OOB or with minor modifications, I'll go through the instructions and write down what colors I want things. This is helpful with the model companies' letter codes, so I don't have to keep flipping back & forth in the instructions trying to find out what those letters, or paint codes, mean. Sometimes I'll make color changes based on photos, or other manufactures' instructions. For example, Tamiya & Revell of Germany usually have more detailed painting instructions than Revell USA (same kits, different instructions, go figure) or Round2.