Well it sounds like you have done 90% of the work already, TIRES!
As far as when I travel to different tracks I usually run a few tanks with my standard setup so that I can get a feel for the track. Then I start changing tires if my first choice was less than stellar. Then I usually start working with shock packages, oils, pistons, springs, shock mounting location, etc.
Usually by this point my car is pretty good. If time permits I start messing around with everything else; camber links, kickup, toe, antisquat, etc. (if needed of course)
Just take your time and remember to only change one thing at a time. Its a process to make your car dialed, be patient.