One way to practice stropping.

One way to practice stropping is to use a roll of news paper.

There is a trick...

One sheet and one sheet only.

Roll it up with a diameter about the same as
the inner bit of a roll of paper towels.

Practice stropping... go ahead and practice.

Note how "tender" it is.
Too much pressure and it collapses.

Note how forgiving it is.
if you nick it you did not kill a great strop.

Note how narrow it is.
and how obvious an X-pattern stroke is.

Yes you can practice with a $15 eBray rusty bit as
long as the scales are mostly sound. Any razor.

Practice keeping the spine/back of the razor in contact
with the roll/strop.

Practice only the weight of the razor. If you press
the roll will collapse.

Practice the thumb roll. Too much of a snap and you hear
it slap rather than settle down on the strop.

And yes this can be a real emergency strop.

Summary:
Stropping takes practice.
Strop slow and deliberately. Speed only saves
a little time and you are not a professional barber
with five customers waiting in line.
Perfect practice makes perfect, practice perfect technique.