The trigger
The usual trigger is a pass to the full-back or a slow pass across the back line. Circle that pass. The nearest forward closes, and the winger jumps to the full-back.
The cover
Someone must protect the center. If the striker steps up, a midfielder takes the space behind. Draw that shift. A press with all four forwards on the ball is a picture of a goal against you.
The trap side
Choose the sideline you want to lock. Show the touchline as the extra defender. If the press is broken, add one recovery run and stop.