For me, The yarn size needed has always been open for suggestion. As long as you get gauge you are good. But, if I want a sturdy lace or a thin lace there are of course a difference in what I use
notice in the pictures above that this yarn would make a really good thicker weight shawl that would hold up to machine washing and hard labor and stand the test of time...you will see in the picture above how I do my last stitches. I don't thread them in until after I've finished blocking my project so that if I need more yarn to stretch I have it and don't have to worry about tightness in the yarn.
you will notice in the last picture my life line. Yes. I even do them with swatches. It helps me keep track of where I am in the repeat.
unblocked v's blocked of the same yarn and repeat
in the 2 pics above you see how I use lifelines and stitch markers. I normally use stitch markers made of straws and opposite color of yarn, but this color of straw is all I had so there you go.
I used a bright pink yarn to thread thru the last repeat of my 1st chart and that way if I need to tink back I don't have to do the whole thing over, just down to my life line. I made only 1 lace project without them, and I never made that mistake again....ever.