You can try facial yoga. Yoga poses that force your head downwards are considered to give the facial muscles a good workout, along with deep breathing exercises. As a bonus, this helps to keep you looking younger.
You can't spot reduce, but as you lose weight, over all, every part of your body will get slimmer. There are exercises you can do that will tone the muscles of your face to make you look slimmer. Google them on YouTube.
There are also some medical conditions that cause puffiness in the face. Make sure you've been checked out to eliminate those.