I would suggest very little. Mark Christopher Lawrence was guest speaker at our recent San Diego Filmmakers meeting. During the Question and Answer period a screenwriter asked him, “What kind of direction do you want in a script?”
From the actor’s point of view this is true. Actors prefer to interpret lines to exercise their skill
I’ve been working with several script writers lately. I find beginning screenwriters often have an overload of directional indications. It’s much better to tighten your writing and remove most of the directions.
However, at times subtext is not evident and you may insert a brief actor’s direction (often called wrylies).
I love you.
Mainly, to tell the story it is best to keep dialogue sequences tight with minimal direction. For the most part, the context of the situation and the character’s actions should speak for themselves.
If you are keeping the dialogue tight—every word counts, written like speech with no long strings of full sentences—you will give the production team plenty to use without needing a number of intrusive actor directions.
Photo image by Gage Skidmore.