The rule for playing the ball overhead using finger action in beach volleyball is much different than the rule for indoor volleyball.
For indoor, you can have multiple contacts (during a single playing action - aka hand setting) during the first team contact. On the beach, it's not legal to have multiple contacts with the fingers during any contact (first, second, or third team contact).
Basically, you can't legally use an overhead setting motion during the first team contact (unless your hands are super clean). So, when playing a ball coming at you high... you need to forearm pass this ball. In order to play a ball with the forearms above your shoulders, you MUST take the ball off-line.
You do this by performing a drop step.
The drop step allows you to move deep and pass the ball off-line. There are basically two ways to take the ball with the forearms... 1) off-line or 2) in-line.
Off-line is basically playing the ball outside the mid-line of your body.
In-line (also called mid-line) is the preferred technique because executing the pass by taking the ball mid-line is usually much easier.
Taking the ball off-line is the more difficult technique to master, but it's worth the time to practice because once you get good at this technique, you can pass every ball that comes your way.
In volleyball, especially when playing doubles, there will always be a time when you can't get in position to take the ball in-line. You will have to take the ball off-line at some point, so you should learn this skill.
Taking the ball off-line is most often the best choice for passing a deep serve or any ball that you need to move back toward the end-line to pass. Always finish the movement with a drop step and angle the platform to the target.
Focus on lowering the front shoulder to angle the platform. You can also emphasize freezing the platform after you pass the ball.
At first it may feel awkward to take the ball off-line if you have never practiced this technique before, but soon you'll get so comfortable with it, this will be the way you prefer to pass.
For when passing from the right side of the court, practice drop stepping back with the LEFT foot as you take the ball off-line. For when passing from on the left side of the court, practice drop stepping back with the RIGHT foot as you take the ball off-line.