Depending how I feel I switch up my 3rd member between Barret, Yuffie, or Red XIII though I always have Cloud and Cid. Cloud for doing the damage and Cid just because he's funny. Specially in the Rocket Town scene in Disc 2 if he's in your party before you go to the rocket. Talk to the old man who tells jokes, you'll get a good laugh.

Anyways I do it pretty old school, I use Cloud as my main offensive guy with his weapon and yellow materia like enemy skill and double cut etc etc. Then I have my 2nd guy (vincent or barrett etc) as my main healer but also has the most powerful summons in the game like Hades, Knights of the Rounds, etc. Finally I have Cid whose kind of a jack of all trades, powerful weapons, powerful limit breaks but I use Cid as also my main black mage with ultima, contain materia, comet etc etc.