1. Cross audio and power cables at 90 degrees (forming a sort of cross intersection).
2. Label everything especially if using a lot of hardware.
3. If you care about your music, care enough to spend money on it (i.e. don't be afraid of saving some money together to pay an experienced engineer to mix and master your music) I can't stress this one enough. Just because you have the tools to do it yourself does not mean you will get the same results that a professional with a lot of experience will. I can buy most tools a doctor has but that does not mean I can fix myself when I am sick.
4. Monitor at a low level when mixing. The image, the mix, and the feel should come through at any volume.
5. No matter what your friends, girlfriends, spiritualists tell you, really and I mean really look at your environment objectively and realistically. If you live in a flat with no shower, have a drug problem, and don't do much but call yourself a musician and think you are destined for fame, please, seek help.
6. Have friends and interests outside the studio. Are you painting paintings for paintbrushes?
7. When you are tired, go to sleep.
8. Never trust words like 'industry' & 'standard'.
9. Use your ears not your eyes. (Turn the monitor off)
10. Be honest and carry yourself with integrity. Instill the same in your working space and be aware of the energy that you occupy. It will translate into the music that you make.
This is all coming from someone who has worked in 'professional' studios and with 'famous' people. This advice is sometimes hard to take, especially for myself
, but it's good stuff to bear in mind.