Beyond that, it's just emotionally rewarding to treat my party members kindly. Buy/syth up armors and accessories specifically for D&G, give Donald magic boosts, try to run to D&G before I heal mid-battle (since Cure heals both you and party members within the vicinity in KH2 and 3), etc. I assume Nomura didn't intend for the average player to give my two pals that much attention, but it's pretty much why I play them. And sometimes talk out loud to them. Because I'm insane.
"I know what to do, Sora!"
"Not now, Goofy! That bombarding attack's for crowd control, not really for fighting a boss!"
"Time for some magic!"
[FONT=Verdana, Arial, Tahoma, Calibri, Geneva, sans-serif]"Donald, we just used Flare Force, give it a break!"