According to Pikalytics, it depends on what tier are you playing in. Lets say, you're playing gen 8 ubers, then here are the statistics:
The moves statistics
-Play Rough-96.781%
-Shadow Claw-81.721%
-Trick Room-50.259%
-Swords Dance-48.605%
-Shadow Sneak-47.556%
-Destiny Bond-47.550%
-Drain Punch-12.597%
-Other-14.932%
So I think that Trick Room is great, as it makes Mimikyu eliminate fast sweepers. Play Rough and Shadow Claw are all STAB moves which are mostly chosen. Swords Dance with Disguise is a great combination so it can make it more powerful, but Dragapult with Infiltrator is all it takes to OHKO this Mimikyu. Shadow Sneak would be good to go first when your opponent has little HP left, plus Shadow Sneak has STAB, so it many people chose this. Destiny Bond, well, I wouldn't say this move is a waste of space in your moveset, but, if you utilize it correctly you might be able to work out a strategy with it, which few people succeeded to do. Drain Punch is, well, you know what, lets just say it only gives Mimikyu back its HP, though I would recommend using Play Rough and Shadow Claw over Drain Punch. Other moves are well, utilized by their own strategy.
Items recommended for Mimikyu
Life Orb 85.409%
Leftovers 4.682%
Focus Sash 2.232%
Red Card 1.025%
Figy Berry 0.901%
Expert Belt 0.832%
Other 4.921%
This is up to you, as I think each one of them is good if it is corresponding to your strategy.
EV spreads
Brave 252/252/0/0/4/0/ 46.476%
Jolly 0/252/0/0/4/252/ 33.209%
Adamant 4/252/0/0/0/252/ 4.281%
Adamant 0/252/4/0/0/252/ 3.958%
Jolly 4/252/0/0/0/252/ 2.603%
Jolly 0/252/4/0/0/252/ 1.763%
This is also up to you, as it should be corresponding to your strategy.
Teammates
Melmetal-48.401%
Lunala-46.513%
Necrozma-Dusk-Mane-46.302%
Reshiram-44.898%
Ferrothorn-24.570%
Toxapex-23.614%
Ditto-23.206%
Excadrill-23.104%
Tyranitar-21.702%
Coalossal-4.071%
Aegislash-3.118%
Haxorus-1.965%
This is according to your strategy for your ideal teammate for Mimikyu, so just choose one that will help you succeed with your strategy with Mimikyu.
All in all, I would have a Mimikyu with this moveset:
Mimikyu@Leftovers
Ability: Disguise
Nature: Adamant
EV: 252 HP/252 Def/4 SpD
-Play Rough
-Rest
-Sleep Talk
-Substitute
Play Rough-STAB move with a powerful 90 BP.
Rest-Recover
Sleep Talk-Use moves while asleep
Substitute-Use Substitute for your free Substitute (Disguise)
252 HP is so Mimikyu can use Substitute more often.
This is just my opinion-you still can make a lot of changes in it, so no need to try criticizing my moveset, since you still can make your own moveset which is probably better than mine, because mine's I got it from Pikalytics.
Hope you find this helpful :).