If you don't have the resources to create a wooden beam, this is a very cheap and fast alternative.
Construction Materials
Pool Noodle
Tape (if on hard surface)
Instructions for Construction
Simply place (and/or tape) the noodle on the ground in an open space.
Modifications of Equipment
Create the wooden version of this if you have lumber, screws and a drill (see pictures).
Dont build it too high! Learners get the exact same skill practice at a low height as they would at a higher height, and are more motivated to practice and feel safe.