There are many types of cradle and different ways how to apply. If you are in top possition Plant one of your hands behind the corresponding knee of your rival. With your other arm, apply pressure across your opponent's face with the forearm, and lift their head, moving it toward the knee that is pinned in position.
When your partner's head is close enough to their knee, slip the arm behind the knee under their leg, and and clasp your hands. One arm will be around the knee, and one around the head.When you have locked your grip, rock backward, so that your opponent's back is to the ground, and you are off to the side, with your grip still locked. Putting pressure on your opponent's side with your knee and extending your arms outward, while keeping them clasped, will tighten the cradle.
When your partner's head is close enough to their knee, slip the arm behind the knee under their leg, and and clasp your hands. One arm will be around the knee, and one around the head.When you have locked your grip, rock backward, so that your opponent's back is to the ground, and you are off to the side, with your grip still locked. Putting pressure on your opponent's side with your knee and extending your arms outward, while keeping them clasped, will tighten the cradle.
Best rival to finish him by cradle is wrestler with nice body. You can check over his muscles while you will be tightening the cradle hold.