Chopsticking the soil so that it fills all the air pockets.
I had a pine I dug 2 years ago that didn't put out any growth and started to weaken. When I transferred a chopstick with soil fungi into its pot, the chopstick just shot down to the bottom of the pot. Turns out that I didn't properly chopstick it underneath the trunk. So when I did, it perked up a week or two later and it started producing buds.
Never making that mistake again.
Better to spend that extra hour, water, and do it again next day just for good measure. The roots are still in stasis anyways.
It can make a huge difference.