My daughter has this problem and I searched high and low to find a solution and found several options. Firstly, certain coloring techniques combined with the following cuts actually help, such as ombre, balyage and strategically placed highlights. lob (long angled bob), asymmetrical bob or angled bob (long in front, shorter in back or if you want to have long hair get a disconnected cut. These actually are smart ways to add volume to the back of the head, which hides the flat aspect. The lob and varying forms of bobs use your hair to create layers underneath, which actually pushes your upper hair up, while still leaving it long enough to disguise your flat head. The disconnected layers haircut, which means you would add dramatic changes in the length of your layers around the back of your hair. However, I personally feel that going with different types of lobs and bobs are so much better. You can also do a dramatic side part, where you have tons of your hair parted and swept over to the other side and back, bringing in volume that way. The best option by far is to talk to your hairstylist to make sure they know you need maximum volume in the back, then they can go over the options I mentioned based on your face shape and even color to help. Ideally, choose a cut that is low maintenance. For several years I kept my hair short with angled bobs and asymmetrical angled bobs, if you go to a hairstylist that knows what they're doing and tell them what you need but you don't want to have to spend a million years on your hair everyday, you will be able to have that happen. I had one haircut where all I had to do was blow dry with a round brush the 1st layer in the back of my head and the layers beneath always air dried the same way. I also had ones that I just needed pomade or another product, scrunched my hair and it was done. I have partial flat spot back there too. I keep a folder now with pictures of haircuts that work for my daughter. That way if she decides she wants to change it up, we can. Make sure when you pick out of these that you keep in mind your face shape. Remember color, texture (wavy, curly, perm, straight) etc can all help too. I hope this helps you and anyone else who is searching out there!