Okay:
First thing first: In teams, always have the bell ready. It is the only fruit that really matters in teams. When teamed with Kirby, start the match by walking into his inhale so you can both have bells ready for stupid combos.
It is important to note that you will completely stop momentum when you hit someone with a bell.
Anyway, simplest one first:
-The 0-death grab combo: As we all probably know by now, we cannot regrab an opponent who just got grabbed within a set time period, meaning grab release to grab release no longer works.
Kirby/Pacman has a way around this: Kirby Dair takes FOREVER to end and Pac Man's grab has a lasting hitbox. This allows you to wait out the grab immune period while they are in Kirby's Dair then grab again. PacMan Dthrow>Kirby Dair (Really easy to hit since Dthrow has the same trajectory at pretty much all percents and has low enough knockback that Kirby Dair always overrides the Dthrow knockback)>PacMan grab>repeat until kill %.
At kill %s, you should do Fthrow (since it has set knockback and will always put the opponent in the exact same place regardless of weight, DI and %) into Kirby's stone for the kill.
This pretty much kills all 2v1 situations.
-Comboing off of Kirby's grabs:
We already know Kirby can combo off of Pacman's grabs easily and set up Pacman grabs just as easily. Even if you're in a 2v2 you can set up shorter variations of the first combo, but how can Pacman combo off of Kirby's grabs?
*At 0-20%, Kirby Fthrow>Pacman Utilt works and leads into many other options, such as DJ Kirby Fair>DJ PacMan Uair, or Kirby DJ Dair>Pacman pivot grab.
*At most %s, Kirby Bthrow>Pacman Usmash combos, though the higher the % the stricter the timing.
*Bthrow>Pacman Bell can work, but is harder to pull off since it requires strict timing to not also hit Kirby..
*Kirby Dthrow>Pacman Bell leads to a lot, as does Uthrow>Pacman Bell
-Obviously both characters can combo off of the other's bells to extend combos and set up kills. Kirby Utilt is a great way to set up bell follow-ups, as are both characters' dash attacks and as previously mentioned, grabs.
I actually have to go but I'll finish this post when I get back.
EDIT:
Okay, I'm back so time to continue:
-When Kirby has an opponent offstage, let him deal with gimping the guy (Kirby's Dair is SOOOOOO good for gimping) and instead put up a hydrant and trampoline between the other player and Kirby so that he can gimp un-interrupted. If you have the bell ready, then jumping over the hydrant/trampoline combo becomes even more difficult.
You can also throw the apple at the recovering opponent if they do somehow manage to get below Kirby.
-Pacman's DA allows for a lot of team combos and is fairly easy to land. If Kirby has a bell and is ready for it, he can catch the opponent flying out of DA low enough for you to follow up with Pacman's Usmash. Otherwise he can get easy Dairs/Bairs/stone follow ups.
-Pacman's jab combo is actually a really good way to start team combos too. pacman's jab sets up the 0-death grab if Kirby Dairs, but can also set up quick team combos if Kirby Bairs or Nairs the opponent back to you, allowing you followups as well depending on percent.
-All of Kirby's tilts can set up team combos if you're close/paying attention.
-Trampoline can allow Kirby to safely use stone. Putting a trampoline down if your Kirby ally is being juggled can help him reach the ground again because of this.
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Basically the greatest assets of this team are that:
1) Both can very easily combo off of the other, even if the players aren't paying attention, and get some truly ridiculous stuff if they are.
2) 0-death grab combos.
3) Double fruits, and more importantly double bells (Although other fruits can be good as well). Kirby is especially good with this power.
4) Pacman has good stage control while Kirby dominates offstage.