I'm not very good with the blanket stitch yet but I find practice is the key. Just take some sample pieces & practice a lot. Also go slow. Another helpful thing I found was you tube videos. You can get tons of tips watching them. As for the thread if I use invisible, I use the YLI nylon but I'm sure there are lots of others. That is just what I bought. Also if I use cotton thread I use Aurifil. It is a little thinner or I have used my embroidery thread which is also thinner. I have just experimented, practiced & watched videos in a nutshell. Every time I think it looks a little better