What books are available?
What level are you making the build for?
Melee build or ranged build? If you do melee ... look at going into .. dervish? from Complete Adventurer. There's a feat ... not sure where it's from, but allows two weapon fighters to make an attack with each weapon on a standard action attack; I don't remember if you can use it with Spring Attack.
If you do ranged, pick up Manyshot and Greater Manyshot(as manyshot, except precision damage applies to each attack and you can get multiple crits), Greater Manyshot was printed in the XPH, but is a general feat - it's in SRD.
Definitely pick up the Ranger/Scout hybridization feat.
Max out your Tumble ranks
If the DM allows you to use magic items from the 3.0 Arms and Equipment Guide (some do, some don't), there's a very handy item in it; I believe it is the Sparring Dummy of the Master and costs approximately 35k - it allows a character with at least one level of monk to train with it for an uninterrupted week, and then be able to take a 10ft step/adjustment whenever a 5ft step/adjustment could be made - this would allow you to take full attacks with skirmish
