THE BIG CAUTION!
WHO YOU ARE AROUND
If you are around people with poor standards in any area, your automatic comparing mechanism will have you using those standards to form lower standards that you would have with people who are higher functioning in the area.
You've probably heard over and over and over that who you are around will affect how well you deal with life. But we fail to heed the importance of this. It is vital, vital, vital.
A STANDARD FOR BALANCE
Some people use "time spent" as an indication of balance. However, I would suggest that balance is based on the "net" (positive minus negative) of what you get out of something.
For instance, you would keep on doing something that is giving you a high yield until you see that there is something else to do that would give you a higher yield in terms of the results you want. (Of course, you wouldn't keep doing your music practicing to the extent it caused you to not make a good enough living monetarily.)
HOW DO I IMPLEMENT THIS?
Although you can set it up in other reference notebooks (such as the Planning Notebook), these are better placed in an easier reference notebook called The Reminders Notebook. You simply put the items you want to review and follow behind a tab, per the table of contents for that notebook, and then review them sufficiently so that you are familiar with and/or have memorized them. As you live life, you can access these standards as needed.
It is best to organize each section of the standards section into separate pages for each area of life you have them in, so that they are not lost in a massive, undifferentiated list!
Good fortune to you, for if you implement this, your life will improve markedly!