Bullet selection, distance, and not taking risky shots That sums it up nicely.
I've only killed a couple of deer with a 223 and it worked fine. I have killed around 30 deer and some antelope with the 22-250. 22-250AI and the 220 Swift. With the 243 Win that number is 60 to 80 deer total and a couple of antelope. Range was from a few feet out to about 325 yards.
I did kill one antelope of a 30/06 with a 165 boattail that went about 400 yards with a heart hit. Never had a hard recovery or a lost deer using any of the 22 Cal. or 6mm's.
I am partially color blind and I am at best a poor tracker. With the 22 Cal I use a standard 55 grain soft point and limit shots only to behind the shoulder double lung. The bullet liquifies the lungs and normally it's a DRT or 30 yard sprint max. With the 243 it's the same shot placement or into the shoulder. With broken shoulders or liquified lungs most are DRT or very short sprints.
All of my near lost or hard recoveries have come for using bullets designed for much larger game in a 270, 30/06, 338 Win Mag and a 375 H&H Mag.
From 1970 to 2010 I hunted on 3,000 acres of deer rich river bottom land. The landowner required that you purchase and use all available bonus tags and party hunt. Deer harvest was normally 60 to 75 per season. Shot placement was the number one reason deer were lost or a hard recovery. Funny how all those "perfect" shots when recovered later were far from perfect. It is truly amazing how far a deer can go with a single lung hit. Same for legs shot off and liver and gut shots. Poorly hit the will to live is strong and animals can be shot to pieces and keep going. That being said I have never seen a double lung hit with a bullet that actually expanded go very far. Having hunted with a large number of different hunters is always surprises me how little some know about deer anatomy.