Choose a pull-up bar at a reachable height
Start with full hang, arms straight, shoulders down and back
Grip the bar with palms facing away (or toward for chin-ups)
Engage your core and brace your body to prevent swinging
Pull your elbows down and back toward your sides
Continue pulling until your chin is above the bar
Keep your chest lifted and avoid shrugging
Lower yourself with control until your arms are straight again
Repeat for the desired number of reps
If needed, use a band-assisted pull-up or a chair-assisted pull-up
If needed, do negatives: jump up to the top position and lower slowly for several seconds
Rest between sets and stop if form breaks (swinging, shrugging, or losing control)