This video was published with permission of Wu Jingbiao, current World Record Holder in Snatch 139kg at 56kg bodyweight.

I tend to listen to technical advice from guys with slimmer built like him... just my bias.

Subtitles by our mutual friend - Qiushi.
Please follow his Instagram accounts: @jingyi_weightlifting_club and @wu_jingbiao_weightlifting

Major points from video:

Wide squats with toes out targets inner quads
Narrow squats with toes parallel target quads and glutes
The narrow/wide squats are assistance exercises - check out my previous blog post here and here
Hip muscles (tight) prevent from collapsing in deepest position (going lower without control doesn't mean better)
Back is tight - no surprises here, you'll hear him saying "yao bei" many times throughout video
Torso upright - again, not a surprise
Keep air in your chest

If you want to ask a question related to this video, I will try to forward it to Jingbiao with help of Qiushi.