Catching with anything other than your hands is always very impressive & unexpected by an audience. This catch in the crook of the elbow is one such move which along with the Shoulder Trap, Neck Catch or Foot Catch will provide a nice pause for applause in any routine.
The Ebow tip catch is also another elbow catch but instead of catching a ball in the crook of the elbow you bring your arm up & catch the ball on the underside of the elbow.
The Easy Way
As always start with one ball. Gently throw it up to peak on the opposite side at just above head height & fall a few inches in front of or to the side of the opposite shoulder. As it peaks, stretch your other arm diagonally up & outwards to meet the ball with the palm of your hand facing towards you. Place the crook of your elbow directly underneath the ball. Just as it touches your elbow begin to bring your arm down to cushion the fall while closing up at the elbow joint to squeeze the ball between your bicep & the inside of your forearm.
It is important to position your elbow under the ball in the right place. Watch the ball from the moment you throw it & closely follow its path into your elbow. Don't try & catch the ball too high up either, wait until the ball is at eye level before squeezing with your arm. If the ball doesn't fall to rest in the centre of the crook of the elbow it will be hard to keep a hold of. If it doesn't fall in the right place the natural reflex is to squeeze tighter. Don't squeeze too tightly especially if you are using solid balls or the ball may pop out to one side, go for control rather than brute force.
If you find yourself running out of space to bring the ball to rest because your arm can't go down any further, try bending at the knees &/or leaning your upper body forward to help cushion the fall.
As you practise catching, everytime you make a successful catch practise throwing the ball back out from the elbow. Just quickly straighten your arm out directly in front of you as if throwing a boxer's jab but with your palm facing straight up. If your arm is twisted the ball will fly off to one side, if it is pointing down it will fly forwards & if you punch upwards it will go over your head.
Once you can do it with one ball try making an elbow catch from a three ball cascade. Juggle a cascade then make a catch but hold on to the ball in your hand, throw the next ball from the opposite side a little higher to give yourself time to place your arm underneath it to make the catch. Hold the ball in your elbow for a couple of seconds then throw it back into a cascade.
A more difficult use for this move is to replace a catch & throw with your hand with a catch & throw with your elbow. Juggle a cascade & pick a ball. As you throw the ball before it, continue the upward motion of the scoop with the arm to place your elbow underneath your chosen ball. Cushion the fall & hold it gently. You will probably want to immediately launch the ball back up as soon as you have caught it but you have to WAIT UNTIL THE NEXT BALL PEAKS BEFORE THROWING IT. If you don't you'll end up throwing two balls from both sides simultaneously which will make it difficult to continue the cascade.
The Hard Way
The Hard Way is exactly the same as The Easy Way except that instead of closing your arm up around the ball, you keep it outstretched throughout. This means that you have to cushion the fall of the ball down into a BALANCE rather than a hold. This way looks much nicer to an audience because the ball is more visible once caught.
Hold your arm out straight with your palm up so that the pit of your elbow also faces straight up. Place a ball into that pit with the other hand. If you are using beanbags then it will probably sit there quite happily but if you are using solid balls then it will roll off if you wiggle your arm a little. Practise swinging your arm from side to side at the shoulder & turning round on the spot, keeping the ball in place all the time.
Now practise throwing into a hard elbow catch, the throw is much more important now & has to be just right. Try to throw as low as possible, the shorter the distance the ball has to fall to get to the catching position the less time it has to accelerate. If the ball only has to fall a short distance your arm will only have to absorb a small amount of force to bring the ball to rest. Exactly like before, reach up, position the pit of your elbow underneath the ball & ease the ball to a stop, but keep your arm straight.
Catching The Hard Way can be fitted into a cascade just the same as The Easy Way.
The Shameless Cheat Way
Juggle a cascade, make a High Throw. Stretch out one arm & Let the high ball fall behind the elbow, with your free hand quickly place the ball it is holding onto the outstretched arm & catch the high ball. It is amazing how many people fall for it.