I've got a good amount of his mechanics down... but I can't seem to juke like I've seen some of these high elo players do in the youtube videos. Any tips?

Always bring wards and know how to use them

Q jungle camps, always carry wards. You'll figure out how it works sooner or later

Wriggles. Pay attention to both enemies and allied minions/champs/wards. One of his biggest advantages is his mobility.

facecheck 1v5, then flash over wall, then place ward down, and press w
pro juke

have your ward slot smart casted ._. so you can smart cast ward and w at the same time also q ing baron op

You can use Q on minions over walls in the jungle as an escape method. I've always seen people do it when clearing but rarely see it as often as it could be as an escape.

One does not simply pro juke with Lee Sin.

A lot of it is working on reaction times, smartcasting, and being very aware of targets you can dash towards to in your surrounds.

Looks like I just need a lot more practice.