- No octaves.
- Each tone of a given row must be used once before moving onto the next row.
- No repeated tones, except for motivic repetition.
I do, however, change things up to try and break the monotony of the music (Because, let me be honest. Twelve-tone music can grow boring fast: especially if composers use just one row for a piece or movement.). I often include two different tone rows at the same time. Sometimes, I bend the rules a bit and move some of the tones of a given row out of order to try to avoid instances of octaves or repeated tones. This approach usually works for me when constructing intervals and chords.