How do you secure your thread when you begin a new one? Specifically, do you or have you ever used a waste knot?
I don't knot and I don't use a waste or away knot. I leave a tail and then stitch over it to secure it to the fabric. I learned to do it that way and it works best for me.
If I'm using a solid colour and I need two strands of floss, I'll use the loop method.
Lately, however, I've been stitching fairly exclusively with Vikki Clayton's HDF Silks... so...there's been no need for that!