After my buddy Scott, A&P for a major carrier, saw my tie wraps all over the engine compartment, he nearly passed out.
Immediately deemed "unacceptable", I was forced to put these clamps in. Come in many sizes. You order them in 16ths. example. a #12 is 12/16 or 3/4' clamp.
Be ready with various needle nose pliers. These are a bear to get in. I have about 50 of them in the engine compartment alone. See the engine thumbnails page for photo's of the clamping work.