[Insidious]

Hey Guys I have only been playing Sc2 for a couple of weeks, And Im trying to develop my protoss gameplay as much as possible.. I ranked silver straight away and i realise there is a lot of noob tactics to rank up eassily however I want to learn (not just win) as a result I was wondering when engaging an enemy i read that it is good to use force fields to split the enemy army into smaller groups.. However when I "A" move with my army Hotkeyed #1 sentrys #2 and HT's #3. I try to use Force Fields to split the enemy but because I am holding shift the sentries do not forcefield until after the Attack move has resolved. My question is this.

Is better to have sentries hotkeyed as 2 issue a stop command and then chain forcefiedls across the army using shift+F+spaming clicks...
Or is better to attack move and then just F+click+F+click+F+click+F+click+etc..
Or is there someway to micro this better so I can use force fields to there full potential??

Thanks in advance