Start off with the two small golems besides the top (purple) or bot (blue) lane then go to the wraith camp near the middle lane. Go then t the wolves camp. Repeat this route. Remember:always be watchfull and look for gank opportunities from you AND from the other team. This will allow you to gank and to prevent ganks on you or on your team. You must prioritize ganks on the middle lane. At level 5, recall and buy madred's razors AND potions. Go then to the blue buff golem and kill him. Then, do the jungle route again including the blue buff and the red buff. once you reach level 10 (summoner level 30 do it at level 8), you can solo the dragon. Place the ward from wriggles lantern to secure the area and, in case of gank, flash throught the wall into your jungle or to the lane. Also, don't forget to get potions every time you go to your base until you reach level 6. At that level, only buy them if you need them or if you want to solo dragon. At level 13, just stop buying them (high level summoners can stop way before that).

You can change youmuus ghostblade int phantom dancer, but I like youmuus because of the money given by avarice blade that helps buy items faster. If there is a tough tank in the ennemy team, you can swap infinity's edge with black cleaver.

With the jungle build, you can use flash instead of ghost, but i prefer ghost because of the obstacles there could be in the jungle. You can also take exhaust, but i don't recommend it, because it only targets one person and it's not useful when you are chased by two or more persons. However, it's a good chasing spell. Some persons also prefer ignite rather than exhaust. I personally don't like that spell but it can be useful in a ranked game against some healer or support champion. Cleanse can also be useful in some situations and I would recommend it because Master Yi is rather squishy and cleanse is a great escape tool even if Master Yi's ultimate does take out negative crowd control.