A warmup by definition is getting the party ready and prepared for exercise. Relevant movements to raise the post would include use of a rower or a bike which predominantly engage quads and glutes. Typically this part of the warmup would only last 3 to 6 minutes as Weightlifter's are not used to cardio!
This would typically be followed by some specific mobility exercises as demonstrated in my video. Movements should be dynamic in nature. It is necessary to address each body part in turn to include, wrists, elbows, shoulders, neck, back, hips, legs etc.
Once a dynamic bodyweight warmup has been completed we then move on to a bar. The first exercise at the start of the session is usually snatched related, therefore the dynamic bar work would include overhead squats and snatch balance. Once a few sets have been performed on each of these movements we start the session and increase the weight gradually before reaching top weight. We would aim to hit between eight and $.12 per exercise, only three or four are normally on top weight. The rest are considered warm-ups and unnecessary to achieve a decent overall weekly training volume.