I've tried to read as many of these posts as I'm able (I do have a full time job!) but I've not seen anyone mention using a wet wooden toothpick to help turn "needle-turned" hand applique. It was a trick I was taught during a class and it has saved many bad words. Use a wet wooden toothpick, either from your mouth or for the fastidious, use a small vessel such as a shot glass, and use the wet end to tuck under the edge. It's awesome for those pesky stray threads that won't stay put.