In order to do anything without thinking about it you will have practice the technique while thinking about it until it becomes instinct.

Footwork drills will help. Before you spar and even in between rounds of sparring visualize yourself doing things right technique wise and remember how it feels to do these things right when you are just doing drills.

First off you have shadow boxing to practice proper technique and then while doing any bag work.

Also, I know I always recommend people to YouTube but its a good place to look up boxing footwork drills. It will be much easier for both of us for you to just go there to look it up and you will likely understand it better.