Hello everybody. I wish to share my wisdom with you...
Try maxing out Crono's speed, giving him the Rainbow and the PrismSpecs, and casting Haste on him. You could also give him some magic tabs and have him cast Luminaire.
Also, I like to give Marle the PrismDress and Safe Helm, because I really rely on her for healing.
The ultimate defensive party, in my opinion, is Crono, Robo, and Marle. Lifeline and Cure Touch are incredibly useful for staying alive. Ice Tackle can do some major damage, and Crono with the combo described above helps, too. If Marle has Prism Dress and Safe helm, then this party can't be beat.
That is all my wisdom, until i think of something else. If I do, I will edit this post to include it. If anybody else has any tips, item comboes, etc. then post them here if you want, or be a miser and keep them secret.