Personally I find an extensive warm up to be absolute imperative for the Olympic lifts.
I tend to row on the rowing machine for a couple of minutes first and then execute a dynamic warm up consisting of a dip, shrug to dip, shrug, high pull, to dip, shrug, high pull, muscle snatch sequence.
Then I do some dynamic mobility work and glute activation exercises.
For me, warm up sets are easier to underdo than overdo! I start very low weight for 5 reps and go up as I feel. I drop the warm up reps to 2 and then 1 when the weight approaches my working set. Typically right now I end up doing 6-8 warm up sets for snatches and about 6 for cleans and jerks.
The warm up takes me about 15 minutes but it’s all worth it!