Fusing maj and min pents give you maj scales and modes quickly, plus one or two notes and phrasing. Always Maj or min 3rd and b5. Lean to whatever is your preference or what is needed (style of American music). There is very little theory involved in this concept. In most circumstances, harmony or chords move in a consistant manner. Fused pents give you, most of the time, the maj, hm, mm, scales, just altering one more note, not limiting at all. Not a catch all, but an excellent place to start. Excellent phrasing need not be any longer than 4 or 5 of the right notes.