Reverse applique can be done by hand or machine, just like regular applique. The only difference is how you layer the applique pieces. With regular applique, you cut out shapes to sew on top of a background fabric. With reverse applique, you cut the shapes out of the top fabric, leaving "holes" that you applique around, sewing the top layer on to a background fabric. If you needle turn, then you have to clip any curves to get them to fold under 1/8" or so. I've found that using pinking shears works great for appliqueing curves.