As a knitter/spinner and weaver - I suggest what some others have suggest - "unspin" the yarn ends about 6-8 inches. Tie the "pieces" then weave them into the stitches - you can tie often if you wish.

I've not tried Fray Check with yarn - but I'd have to think it would work well (I am going to try this on my next project).

I am a knifty knitter kind of person. :)

i have used fray check it doesnt get hard

I leave long ends and then I weave them in maybe 5 or 6 inches then I catch the next loop and weave the the tail back on itself the same distance and cut off the remainder.

I've done that too and tried it on these lacy blocks, but it showed.

I always do a square not before weaving thread after a lot of washing the weave minght come out but the square not does not. When I am adding yarn I push it through the other end with yarn needle and it is locked in when you knit or crochet with the joint