I have experience with VGC, so if this isn't for VGC take my advice with a grain of salt. (If it adds anything, I also have a lot of experience with/against Garchomp within VGC)
general things: -max speed so you don't lose speed ties with other garchomps -rock slide is probably one of garchomp's most important moves (spread+flinch+rock type) -definitely keep earthquake too for the type coverage (hitting steel+rock usually) -dragon claw over outrage (you can't choose your target with outrage)
item: -life orb most notably(imo) lets you ohko other garchomps with dragon claw (of course it gives a general power boost, but that's what I noticed most in trying out items) -choice scarf gives a huge surprise factor against opposing garchomps and scarf salamences (unfortunately, you won't be able to ohko garchomps or salamences through their intimidate) -lum berry is great for absorbing will-o-wisp without having to switch out and gives your team something to absorb a sleep -focus sash/yache berry/haban berry also options if you wanted some potential extended longevity
In VGC, the standard has typically been: Garchomp@Lum Berry/Focus Sash/other Jolly Rough Skin 252atk/252spe/4hp -Dragon Claw -Rock Slide -Earthquake -Protect
Personally, I always found the lum berry most useful in general. But you may be confident in your status absorbing ability with Meowstic on the team, so the life orb power boost could be great.
Choice scarf always took me by surprise the most, but it never really scared me since it would then be locked into an easy resist/immunity. I would run this if you need to knock out/cripple opposing salamences/dragons.
And if you want to extend its lifespan, I'd go focus sash before the berries. I never liked the sash too much though, because I always found my garchomps taking plenty of chip damage because it does have great resistances that I liked to take advantage of.
TLDR: You can't choose your target with outrage.
Dragon Claw and Life Orb..... ok. That helped a lot (I'll look into Lum Berry too if it turns out I have more of a problem with status than I thought). And yeah, Protect seems like the better option over Fire Fang. my other teammates can deal with Ferrothorn and Scizor anyway (zard Y especially)
Yeah, I based the doubles sun team around VGC rules in case I intended to go into Rating Battles or official tourneys. So all the options I had had to be in the Kalos dex.
Official Furfrou of the Omega Ruby & Alpha Sapphire Boards Unless what you're talking about is either food or something bad, it needs more Furfrou
For VGC Garchomp has a difficult time deviating from its standard moveset and EV spread because it takes away from what makes Garchomp good in the first place. It needs Jolly and a lot of speed in order to effectively check Charizard and Kangaskhan, and in doing so, you might as go max speed so you don't lose speed ties. Max attack is also pretty much required because base 130 attack isn't what it used to be, not to mention Intimidate is a staple on any team. Lum Berry and Rocky Helmet are the most common items it runs, and also for good reason.