hey, I kinda noticed a lot of dks I know don't know their matchups, so, because i've been around since release and played pretty much every character multiple times, I figured I'd give you my short-hand notes on every character, particularly the obscure/****ty ones
if gimping isn't mentioned, you should go for gimps or ledge pressure (space fsmash while they're on the ledge) regularly
ZSS - can't do much vs shields, one recent trick I found is to never jump in or roll, just foxtrot shields, and punish, and she can't do much about it on the ground. don't try to gimp
Zelda - Don't jump. ever. beat her on the ground or you'll wind up getting usmashed
Yoshi - foostools gimp more than your aerials, just space him out and always keep a punch stocked when you're over 140 in case he goes for a usmash
Wolf - force him offstage as much as possible, try to gimp, might not work but you rack up a lot of damage while he's off there. powershield lasers, it's easy against him.
Wario - don't get grabbed, pivot grab a lot and keep him away with bair, don't let him above you
Toon link - shield his full loop and then punish after that. punch ***** his ground game, and if he doesn't have a bomb you can hit his shield with anything really so long as you space right. ftilt is good here
Sonic - space bairs, grab gimps work better than your normal stuff, get him off the ground and try to keep him up
Snake - downb a lot, shield grab landings
Sheik - i dunno, I just space bairs/punch and i've yet to lose to one
Samus - same as sheik, DI is important cause she can't really kill, don't gimp
R.O.B. - juggle, don't gimp, grab a lot/ledge pressure, keep punch stocked at high %
PT - don't approach squirtle, just kinda grab when he comes on the ground and tilt/bair when he comes form the air, charizard is all bair spacing, move a lot against him. not sure on ivysaur, i try to gimp him but outside of that i don't really have a plan
Pit - no clue, ****ing annoying
Pikachu - grab -> through offstage -> try to bair, it works well. other than that no idea, we have like 1 pika here
Peach - don't let her above you, space a lot and go for early kills, don't gimp
olimar - hit on the landing, upb/downb a lot. when he's offstage wait for his second jump, then bair
ness - I just grab release infinite since they only ban the marth one. if it's banned, i dunno space bairs?
mk - too much to write
Marth - hit on landing, don't gimp (ledge pressure ***** though) basic spacing outside of that. don't let him too close on the ground
Mario - recover high, if he jumps, back air, on the ground space and punish, he kinda sucks on the ground
Luigi - keep him away, get him offstage and bair a lot
Lucas - see ness
Lucario - space, ledge pressure, always look for punches around 70-90 so he doesn't get dangerous
Link - grab a lot, throw him offstage and follow up, just shield his bombs and crap because he can't do much else
Kirby - don't approach at all
King DDD - no clue, I main snake because of him
Jiggs - similar to luigi but she dies earlier
Ike - bait and punish, space out the jabs? we don't really have one and I just go for gimps a lot. don't gimp if he's near the stage
Ice climbers - downb, throw nana away, fsmash her as she runs back to popo
ganon - camp, spotdodge a lot
Game and watch - stay on the ground, grab a lot, don't gimp. utilt beats all his air stuff if you do it right
fox - upb pressure for approaches. really i just go for grabs and try to get him offstage/gimp. he has some tricks offstage, but it really doesn't help too much. bair goes through his side/upb. most foxes are dumb and still dair your shield, just shieldgrab it. I could write a whole long guide on him and falco but it'd take too long
Falco - similar to fox but gimping doesn't work as well. platform camp the first 40% and keep him away, but if you let him too far away he'll just start camping. you'll know where you should be when you get there.
DK - dthrow offstage and either spike or sideb depending on how he comes back
Diddy - abuse SA, hit him on landing, go for lots of gimps with the upb ledge stall/bair
Falcon - don't jump, don't approach wait for his spotdodges on the ground. get a % lead and play campy as hell
bowser - bair a lot and hit him with smashes when he lands, watch out for sideb
I did all of them just in case, but I'm pretty sure the only useful information is on ZSS, Zelda, Yoshi, Wario, the space animals, Toon Link, Mario bros, Kirby, ICs, Jiggs, DK, diddy falcon and bowser.
anyway, have fun