Filming troubles

I came across a few difficulties while filming last week.

1. I attempted to film a head shot of a character screaming however when reviewing the footage they looked more like angry screams then the scared look i was going for. To solve this when i film this shot again i am going to demonstrate to my actor how i want it to look as well as explain the situation of the scene better so they feel they can get into character quicker.
2. Filming in the dark makes creates a grainy, out of focus effect and it is to dark to see what is happening clearly. However i am going to film with the lights on and edited the lighting afterwards on imovie changing the brightness.
3. People keep walking in and out when i am trying to film in areas such as the toilets. I might put a sign on the door to ask the girls to use the other toilet down the hall.
4. I found it hard to work out what shoot to do due to lack of actors or situations making difficult to film. i also felt i was being a little unorganised. To solve this i am going to create plans for the day i am filming to be more prepared for shooting