When we talk about backswings
Full backswing is 12 oclock
half a backswing is 9 oclock
so a three quarter backswing will be 10:30
Generally the length of my followthrough is the same length as my backswing
these will give you more consistancy than trying to hit a slow full swing,as the others have said square face at impact, you cannot hold it square all the way back it will lead to horrible things like swaying , dipping and hands trying to seperate.