Complete Olympic Weightlifting Warmup

Details will vary among lifters according to need, but the following will provide a complete warm-up protocol for Olympic weightlifting, or at least serve as a template for you to adjust as needed. You can find links to more detailed videos about each part in the caption.
The process will include a few minutes of general warm-up, potentially foam-rolling, dynamic range of motion exercises, some static stretches for specific areas, preparatory work for the shoulders, hips and trunk, and finally a barbell warm-up specific to the first lift of the training session.
General Warm-up
Start with 2-5 minutes of low-intensity monostructural work: bike and rower are best because of the lack of impact, and rowing is preferable to bike because of the full knee range of motion and additional involvement of the back and upper body. This is to get the body literally warmer, which improves nervous system function, and to improve blood flow, which increases flexibility. Feel free to extend this time as needed on particularly cold or stiff days.
Foam Rolling
Foam rolling is a somewhat contentious activity. The mechanisms and even effectiveness are unclear, but we do have a lot of anecdotal support of the practice. My suggestion is really simple: try it for a while. If you find it helpful, keep doing it. If you don’t, skip it, or just do the specific areas that do help you. 8-10 passes is usually enough.
At the very least, use a foam roller to mobilize the thoracic spine. Hold your trunk in an approximately straight line from pelvis to shoulders by maintaining moderate ab tension. The idea is to simply get the vertebrae moving independently of each other—you should feel some popping and cracking as you start rolling. Start with the arms across the chest and finish holding them overhead. Resist the temptation to arch back over the roller—most of the movement you’ll get from this will be hinging at the T/L junction rather than the T-spine itself.
Next we’ll run through a series of DROMs—dynamic range of motion exercises. These are a quick and simple way to retune muscle length neurologically, and because it’s constant motion for a few minutes, it continues to warm the body. Do 10-15 reps, gradually increasing amplitude from first to last, and don’t push to painful ranges.
Static Stretches
Generally we want to reserve static stretching for post-workout, but there are exceptions. Notably the shoulders for overhead mobility and the ankles for squat positioning.
Additional static stretching in the warm-up is appropriate for newer lifters with severe mobility restrictions. Concerns about potential reduction in power and proprioception are needless in such cases—a lifter in these circumstances isn’t performing at a high enough level for it to matter, and more importantly, their performance is significantly limited by their immobility, meaning additional flexibility work is only going to improve that performance. In the case of overhead and ankle mobility, we’re stretching muscles that don’t participate in power production for the lifts anyway.
Next it’s a good idea to hit at least a minimum of some shoulder and possibly hip and trunk prep work. External rotation, IYT and similar variations for the shoulders; single-leg glute bridge, Cossack squat, banded shuffles, monster walks and similar for the hips; crunch, hollow or plank variations for the abs, and possibly extensions or reverse hypers for the lower back. One of each per session is plenty, but vary exercises day to day.
Barbell Warm-up
Finish with a series of movements on an empty barbell specific to the first lift of the training session. This is a time to not just continue getting warm, but to practice and reinforce appropriate skills and positions. Think not just of body parts, but of the motions you need to improve and prepare for.
Of course, like training generally, the warm-up should suit each athlete individually—add, omit and adjust these things for yourself to develop a process that’s most effective for you.