I wrapped my headers once. A few suggestions, and I'm sure others can add to it.
Clean the headers well before beginning, don't want to trap crud in there.
Wear long sleeves, eye protection and disposable gloves.
If doing it yourself, leave the headers in place. May be able to get a better wrap by taking them off but you will need a helper.
I started at the bottom and wrapped up, figured water would shed better that way.
The short SS straps are just long enough. I ended up replacing a couple with longer straps cut to length.
I had removed the O2 sensors and fitted bolts long before. I just wrapped over them. Wrap did start tearing at those bolts heads after aging a bit. Just wrap around them, leaving the slit for the sensors & wires.
Soak the wrap for a while before you start. Dye will wash out but don't worry about it.
Many paint them with high temp paint, I didn't and mine did fade a bit more than expected.
It will stink for the first 2 or 3 heat cycles but will stop.
Good luck with it.
