What's a list of good boundaries (examples, situations, activities) that should be used with plates vs. a LTR?

I'm aware that plates are for sex and limited companionship, but where do you draw the line on companionship? For example, would a daytrip to some park, etc. with a plate be a bad idea?

My experiences have mostly been exclusive "traditional" LTRs, so don't want to give plates the wrong idea by doing stuff that feels "normal" to me to do with a girl. But does this mean never going out to eat, not going on short trips, etc?