Get kids practicing in their head first!

Sounds like a weird blog title I know! But today I noticed something in a student that affects some of my students more than others. If I have an enthusiastic student, they are often so eager to play something that instead of analyzing a phrase in their head first, they rush/stumble forward - repeating certain notes over and over and not progressing with their rhythm or intonation in a very efficient way. When I say "practicing in their head", I want my students to approach a piece how they might when they were learning to read a book - to look at the shape of the word first, and imagine how it might sound before saying it. This would mean that they look at an entire bar or group of notes before playing it. To look for the fast and slow notes in the rhythm and sing it to themselves in their head first if necessary. Then they can look at the position their fingers will have to take over the entire bar and prepare their hands on the violin before they play the bar instead of working it out in the middle of the bar. Key words are - Stop, Look, Prepare!!
A way you could make this into a game would be to say that once they have started the bar they are not allowed to stop for the entire bar. This forces them to think ahead - they can compare how it sounded in their mind first with how it sounded after they played it, getting them into the habit of practicing longer sections at one time.