Hmm... For some Metas as well when they are off the stage, obviously try to arrow gimp him, racking up damage and trying to slow down his recovery, Then if they choose to use the *****-nado or Shuttle Gay for recovery, You can attempt to shield him, of course some will be too smart to fall for this all the time, but its a nice try nonetheless.
If you predict the Meta Knight wisely, space with F-tilts since Its Pits best choice for range in most cases, although it is slow, if you think while using it you should be able to pull off a quick attack and can think of your next move.
Projectile spacing is something you have to do against Meta Knight, whether his tornado can get through the arrows or not, they are a necessity against The Purple Skittle and keeps you from getting wiped out by his tremendous speed approach.
Hayang is right, D-tilt is a fast attack and is useful at times against Meta knight, the fact that it also knocks people up makes it possible to avoid possible counter-attacks.
Pit's F-Throw usually connects with the F-Tilt or F-Smash, maybe even another F-throw so thats a nice beginning start for damage.
In the air Pit is usually screwed, your best attack against Mk surprisingly is the U-Air, which has great Priority when he is coming down or doing a glide, and the B-air is your best bet for Kills at low damages to take advantage of the fact that he is going to be doing a lot more hitting then you..
Going back to the arrows, after about 2 or 3 the Mk is going to break through with the *****-nado, so be prepared for a lot of blocking during this match, of course he is going to do his grab and grab combos as well, so spot-dodge and do your A combo during this.
Your A combo is a valuable resource against Mk speaking of which, Jab canceled grabs (very few given Mk's speed), and the triple a Combo is fast enough to counter and knocks him back far enough to be safe after.
The Angel Ring is also a useful damage racker, but only when used right, be warned it leaves great weakness in the wrong hands.
Save your F-Smash and other kill moves for the killing strike, we all want the masked skittle to die as soon as possible...
Pit can get gimped against Mk easy if not smart about it, So you can try to glide, mix it in with the Up B to confuse him, Do pretty much what Hayang said, be unpredictable and I doubt you'll get gimped easy.
So yeah.. those were a few more thoughts about the match-up I guess.
Its probably 70:30 in Meta Knight's favor.