I replaced the internal wiring first before I upgraded the crossovers , this allowed me to experience the change only of the wires . I used Cardas chassis wire , first I used 15.5awg from speaker posts to crossovers and then to the speakers , I then changed to 17.5awg from the mid and tweeter crossover to the speakers . The origianl wiring was 18awg solid wire . I like the sound improvement alot but working with cardas wires means using a solder hot pot which is a little more work .
If your crossovers have Clarity capacitors that's great , I used the newest Purity series on the mid and tweeter and CMR , MR on the woofer ( I upgraded the woofer first before the Purity caps were available ) . You should also consider replacing the resistors with Mills , I had done this after the wiring and before the capacitors ( I tried to listen to each form of improvement independently rather than doing the upgrades all at once ) . I used the original inductors do to size . I also installed Cardas speaker binding posts although if you have the funds WBT posts might be better .
Good Luck