Make your first 15 minutes in the gym matter.
In that time, address 3 things.
Perspire. Your body needs to warm up and sweating puts you in that mindset that you are present. Some people, myself included, don't get into the mindset until there is sweat on their forehead so start there. Nothing complicated, just a dynamic warm up or get on the assault bike, rower, or dare I say treadmill will do the trick and try to be as efficient as possible to warm up and then get to work. This may look different depending on your time and specific goals.
Prime the movers. If this is a squat day, incorporate movements that will accentuate hip extension, foot stability, and core bracing. The primer movements matter so that you can put forth your best effort to address the main focus of your day. There are people that don't have the time but don't expect optimal performance if you can't spare the few minutes to get ready to attack the workout. Dynamic bodyweight exercises, banded or kettlebell work would be a great start.
Address your imbalances/weaknesses. Along with priming your main movers you might have a few muscles that affect your posture and how well you maintain position. Common might be tight hip flexors or ankle mobility. Easy ways to target this are by active/dynamic stretching or foam rolling. If you take a few minutes every day to address these issues instead of playing catch up on 1 day or lost time due to injury just make this a part of the list of "must do's" to save yourself the trouble and set yourself up with quality mechanics.
Improve your training. Improve your life.