Unfortunately many of my quilting friends think of applique as a four letter word ...... lol ...... so I have had to rely on whatever tutorials or classes I could find, of course being left-handed does not help either. (
everything I do tends to be backwards) But I have picked up tips here and there ... always press from the back side, watch how you hold your background fabric, not to tight but loose enough so that it could be pulled from your hand. The type of thread you use is also important. Regular piecing thread is usually to thick, 50wt is better, 50wt/2ply is even better and then there is 100wt silk thread. Now with using silk thread, since it is so thin, there is a trick to keeping it from slipping off your needle. You have to make a knot close to the eye of the needle and since the silk thread is so thin it will not interfere with your sewing.