I usually tie them in and then weave the ends in as I go along if that makes sense.
As others have said, I just keep going until the blanket is the size I want and then finish off with a double crochet border to give a firmer edge.
I find joining squares fiddly but do so on a small item like a baby blanket as the squares can then be of various designs which looks really attractive.
This would under normal circumstances be headline news
Keeping Cool Tips! Let’s swap?


you can crochet garments together rather than sewing them if you would find that less of a chore.
