I do mostly needleturn and don't use a fusible or anything else. I mark my shape in pencil then turn the edges under to the marking.
Elly Sienkiewicz is an authority on this and has many many books on this topic from 12 ways to Applique to beautiful books on Balitmore Albums. She's my go to.
You've just entered the applique zone, be prepared to relax!!! :lol: