My current party is Serge, Kid, and Glenn, and I use Guile whenever Kid isn't in the party. Serge and Glenn can use a Dual Tech called X-strike, a very powerful ability that also references Crono and Frog's Dual Tech in Trigger. Everyone has a full set of Iron armor and whatever accessories are necessary.
I'm also getting used to Chrono Cross's level up system. Essentially, every boss fight earns the party a new star, which usually adds a new Element Slot for each character and provides a large stat bonus. From there, characters occasionally gain HP and other stat bonuses after normal battles.
Chrono Cross remains an excellent game, and I'm looking forward to playing more of it over Thanksgiving break. Look for a review in a few weeks.
