I can not support the idea of spot reduction personally because it is not really possible to move fat from one part of the body alone unless you go in for a surgery (Liposuction). The best way is to exercise and as you mentioned that you are going to the gym as well, you can ask the gym instructor to teach you certain exercises which are focussed mainly to shape up thighs and hips. Those exercises if done in the right manner do help shape up.