I use biostrike on the leader at times, it tends to fall off every so often. If I am prepping for an evening of dry fly fishing, I often put a small tuft of unbraided macrame yarn (like EP fibers, or the stuff from the puff ball strike indys) in a knot along the leader...that stays put.
I have at times pre-threaded flies to tippet, then when I break off or wreck the fly, I can just tie the two pieces of mono together and be right back in business. For example, during a hex spinner fall in MI, you'll have maybe 45 minutes of fast and furious dry fly fishing. Every second you use tying on replacement flies, etc is wasted prime fishing time. To do this you can use a double uni (takes longer), the EZ "blood knot" (which is really an overhand knot, then tie a dropper loop with the overhand knot in the loop, then cut off the dropper loop), or ( brace yourself...) just take the two pieces of line, hold them together and tie a double overhand with the short ends on the SAME side. Looks like heck and doesn't lay out perfectly but it gets you back in the game fast.
Started cheaters many years ago since it made threading midges easier even though I could do it (at that time) unaided. I am now up to 2.75 or 3.0. That creates an issue at night. The focal length on the higher power cheaters means I must thread a fly that's very close to my eyes. UNfortunately, it's tough to get the light from my headlamp where I need it when the fly is so close to your face and the light isn't colocated with your eyes. I was despondent and thought I would have to give up fly fishing in very low light conditions until the answer finally came to me one day..
When it gets too dark to conveniently thread a small fly onto your tippet:
-- fold your leader in half so the thick end and the end of the tippet are together.
-- this will help you find the half way point along your leader
-- cut the leader near the half way point, a little further into the butt end
-- tie on a number four mouse pattern
-- resume fishing until daybreak if desired.