I've become a fan of using 2mm stainless steel rings to join different pieces of tippet line together, or to add droppers.
Only a bit more fiddly than joining with knots, but with several advantages.
I've learned that one make seems to cut the line

, but I've not had any such problems with Riverge rings.
What I do find is that their fiddliness in bank-side tying is a great generator of expletives, especially when the small ring leaps (as if alive) and quickly hides in the vegetation.
The solution I've hit upon is is to tie tags of around an inch of tippet material (or even a tippet length to be stored in a plastic envelope ready for use).
A tag makes handling them considerably less fiddly, especially when pulling a knot tight, then the tag can be removed.
Four or five pre-tagged rings save an awful lot of bank-side expletives (and not so many lost rings).
Another rainy-day job

.