Get your boat speed up with the front runners first.
This is very good advice - getting the straight line speed, tacks gybes and roundings sorted first gives a firm foundation on which to build tactics on (starts, favored side of course, inside lines, covering etc). I had to opportunity of practicing all winter long with two other like boats skippered and crewed by great sailors. This really accelerated our learning curve on a new boat. Now I can start to think about the tactical stuff and actually execute it. Previously I'd have tactical plans...but not enough speed or technique to use them (blown tacks etc).
This past weekend I crewed on a Hobie 20 in a one design class. At times we had the same or better boat speed than the guy who won, but he had better tactics and made less mistakes...so he got 5 bullets. On the other hand our boat speed rescued us from some of our mistakes so we ended up with second place.
Chris.