For several years I have been using snap clips at several stages of the warping process. I find that it much more efficient to secure bouts with these clips than by tying them in the usual manner. Less finger manipulation is required and at this point in life that's a good thing!
If you look to the right in the photo you can see where one bout has been sleyed and I've refastened the clip to that bout on the other side of the reed. Snap clips are available in any store that has a section for hair care supplies. Some of the cheaper ones, such as those available in dollar stores, are not as nicely finished and have rough areas; avoid these.
I posted this suggestion on the Weaving Hacks page on Facebook and was bowled over by the positive response so I thought I'd mention it here too!