I run into the same issue, especially with horizontal perches, where it can be hard to predict where birds will land.

Additionally they often immediately jump to the feeder or to the ground leaving no time to move the camera and get a shot.

One technique that works for horizontal perches.... use a limb with lots of small branches and trim a few to create a space for perching where you want it.

Vertical perches are a bit more predictable as birds like to land at the top but the woodpeckers often land lower, scurry quickly to the top and then jump to the feeder. Also the woodpeckers often hide on the far side of the vertical perch and just peek out. Every so often one will perch in a good position and be still for a few moments. ( I use a couple of cheap plastic Christmas tree holders for my vertical perches )

Leaning a vertical perch will encourage birds to land in a favorable position as well.

You are correct about motion ... Cardinals here are also very sensitive to motion.

Another trick (which I have not done for a while) is to drill a small hole and fill it with seed or suet .... birds will of course perch there to feed.

I have about 4 acres of woodland and a small creek behind the house so there is an ample supply of perches laying on the ground close by.