A while back, when I first started (attempted) Intarsia, I wanted to learn all "how to." Watched Youtube vids, bought and studied the books, and practiced a bunch. It would be great to take a class from one of the experts, but it is not a possibility for me. The biggest challenge was sanding and contouring. I found Judy Gail Roberts has a DVD on contouring Intarsia.
As I was ordering it, I saw another DVD she has on Scroll Sawing for Accuracy. I don't spend cash easily (I have a hard time throwing out used bladed). I ordered that one too, and I am glad I did. I have been scrolling for 6-8 years and learned a lot. I highly recommend it to newbee's. If you are thinking of trying Intarsia get both! Have I arrived, not even close, but these two have made me better.