my winter system is and 8'rod, baitcaster, and braid. Sharpie marks last almost forever on hi vis braid. I was fishing 30 to 35 feet deep and with the braid, a bobber stop didn't seem feasible to me. Machinist's use dye marker in their work, you might look into that as being more permanent on mono or flouro.
To measure, I use the length of the rod, then thumb the spool and hold the reel in the middle of my chest. Grab the line with the other hand and extend it out as far as you can get it to go. For me, that's real close to 3 feet. Or mark a foot and 2 feet from the front of the reel on your rod. When fishing deep, the marks save a lot of time.
Creativity is just intelligence fooling around