You will get lots of differing views and what is right for me might not be right for anyone else but here goes...For me...
1. It is a horrible idea to just screw the cue and start playing.
Warming up is fundamental to virtually all sports and pool is no different.
My warm up routine for matches involves shooting NO shot that I can possibly miss. All I care about is getting the kinks out...getting to FEEL my stroke and to test the table for speed.
It also might get in your opponent's head if he never sees you miss.
2. I have a set list of my Magic 7 Core Fundamentals. I won't get into what they are for me because they might not be right for anyone else.
So, just make your own. When you are in dead stroke just take note of your stance, your bridge length and FIRMNESS (lots of players get lazy and have sloppy, loosey goosey bridges...grip pressure..."finish position" i.e. where your grip hand ends up in relation to your body on your normal stroke...
The list could go on and on but there is one thing that should be on everyone's list...feel ROCK SOLID STEADY throughout the entire stroking process all the way to the finish position and THEN SOME.
Most matches are LOST by unforced errors...not won with spectacular shots. And most shots are dogged due to a lack of focus/dedication to EACH shot or because of body movement or both.
A repeatable stroke is a physical/mechanical process that should be identical from one shot to the next and is highly subject to being broken down into component parts.
So, bottom line, if you have a conscious awareness of what those components are, the only reason to be "out of stroke" for more than a shot or two, is purely mental. You have somehow lost confidence...are in a bad mood for one reason or another...and often for no apparant reason at all.
On those days, all I do is just FORCE myself to care only about ONE thing....the next shot. Hell with winning. When your are down 7-1 in a race to 7 you can STILL make ONE shot...the next one and can win ONE rack...the one you're shooting in.
Regards,
Jim