Fig: My homemade stropping leathers in various stages of completion (buffing wax)
Basic information about stropping leather as an abrasive can be found here. This is supposed to be about handling. And this one has it all.
first of all, the leather must be coated with abrasive in the first place
and whenever the layer has worn off, the abrasive must be renewed (which is actually the same thing).
In principle, there are three types of coating:
no coating: the simplest and most fine-grained type, but just not very flexible
a reasonably thin emulsion: pleasant and easy to use. Unfortunately there are mostly only
very expensive diamond emulsions (e.g. from Jende Industries), or
semi-obscure other ointments and tinctures, of which it is not known how fine-grained they are.
or friable buffing wax, which is reluctant to spread, but at least a bit easier to assess.
Normally wax is used. It's amazing how it resists giving off a nice finish. You can do whatever you want: thick wax crusts always alternate with bare leather. Hence my merciless advice:
first rub a lumpy surface as well as possible (possibly warm up wax and leather a little bit)
then try to spread the wax with an iron with the addition of leather oil. When the oil is dry you are satisfied with what you have just achieved
and slowly start researching for more liquid paste.