Guitar Notation Help

Hello, I'm writing a piece for two electric guitars and have encountered some things that I'm not sure have a standard way to notate them, so I thought I would get people's thoughts on what would be best.

1. The piece is played primarily with picks, but occasionally I want to specify that a certain chord is played with fingers, or with pick and fingers together - should I just write "with fingers" each time and then "with pick" when it goes back to using a pick?

2. Palm mute - I was thinking of just writing "p.m." followed by "ord." when it gets back to normal (and having a performance note at the beginning saying "p.m. = palm mute").

How does that sound? Are there any 'standard' ways to notate those things?

There are some examples of palm mute notation here:  https://en.wikipedia.org/wiki/Palm_mute

And here's a good chart of all sorts of guitar notation that you might find helpful:  http://www.frankgambale.com/guitar_notation_legend.pdf

(I play clawhammer banjo, so no picks for me.  Can't answer that one for you.)  (:

Thanks, this is helpful.