There are books describing the process, but I don't have any so I can't tell you their names. You should be able to find them if you do a google search. Basically the snippets are placed where you want them and the entire quilt top is covered in a sheer fabric, then densely quilted right over the sheer fabric (which remains there forever) to secure the snippets in place.
If you do a search on uTube I bet there are demonstrations there.