In reply to Birks:
Surely the best way to use most pinches is to get off to one side and use them as sidepulls? However, you can’t always; I did a route on Saturday where the start of the crux involved pulling frontally on two fairly mediocre pinches, so I was glad I’ve been training them.
How? By getting a bit of wood, hanging a weight from it using a sling (20kg kettlebell because that’s what I happen to have) and picking it up. Can be varied by changing either the weight or the thickness of the bit of wood. I do this as part of my fingerboard routine.
(Rumour had it bitd that Ron used to do pull-ups on ceiling joists. That would clearly be far cooler)