There are several techniques for applique, including needleturn, starch & template, and backbasting and then there's fusible applique. I am including several links for different techniques. I have taken two hand applique classes and one machine applique class with Karen Kay Buckley and like the starch & template technique; however, I like the backbasting technique, too. I tend to use different techniques in a project, depending on the size of the piece.
http://www.appleblossomquilts.com/ Connie Sue Haidle
http://www.karenkaybuckley.com/index.phpKaren Kay Buckley
https://www.p3designs.com/shop/product/p3-172-off-the-block-applique-book/ Pearl Pereira
There are several applique retreats -- one in Dallas, TX and one called Applique By the Bay in Galveston. I know Pearl Pereira teaches at the Galveston retreat.
If there are any quilts shows near you, check to see if they offer classes. I'm lucky to live in the Houston area, so take classes from teachers I would never be able to any other way.
Jenny Doan did a 4-part applique tutorial which was very good, and I would also recommend the Craftsy classes.
This is a BOM I am currently working on. This particular block was done all with backbasting.