I'm sure some of you have caught onto this, but I'm sure some haven't so I wanted to put it up here. When I first started tying, I used a bobbin threader to push the line through the nozzle when I switched threads. One day I was watching someone tie a pattern on YouTube and realized a MUCH better way. It's simple.

Step 1: Using your fingers, push about half an inch of line into the bobbin tube
Step 2: Pretend the other end of the bobbin is a straw, and give a quick burst of suction to pull the rest of the line through

Your bobbin has now been threaded in 5 seconds without the need of a tool.

Been doing it that way since forever. My first fly tying book (which was a long time ago and written decades before I was born) recommended against "bobbin holders" as they were originally called, since the spool the thread is on is the actually the bobbin. Anyway, a small bit of inner tube under a thumb tack was considered the best way to hold tension on the thread, with the bobbin held in the hand and fed through the fingers when being wound. Having dropped a few bobbin spools and chased thread across the room, I tend to appreciate the more modern method--still, threaders are a waste of time and just another tool to buy or make, then get lost among the clutter. 99.9% of fly tying can be done perfectly well with well-learned skills and vise, scissors, bodkin, and bobbin (holder).

I just run the tip of the thread through my lips real quick so any fibers sticking out lay flat and the tip is one solid mass.