tresome conditioner and shampoo - leave conditioner on for an hour or so - works a treat!
As Choocie says, Tresemme's salon silk conditioner and shampoo are very good for dry hair... they helped rescue The Lovely thick wavy hair when it went through a horribly dry time and I've stuck with them though maybe they won't work the same for your fine hair...
You could try:
washing your hair much less often and in much cooler water;
the Tresemme;
if you have frizz, using some John Frieda extra strength defrizz serum after conditioner;
spraying with Aussie Miracle Luscious Long leave in Conditioner;
colouring less often (or better!);
less heat!