They have some great dry shampoos as well. That can help between washes! Theres this awesome styling product by Bumble and Bumble called "Blow Dry". It has little beads in it filled with a fine powder. You put it all over your hair and they break up as you blow dry it. That stuff has been a lifesaver for me. I can go 3 days between washes if I use that!
Using shampoo strips your hair's natural oils, which triggers it to produce more. This causes an increase in the amount of oul in your hair. Try going with just water for a while.