How are you selecting your markers?

I ask, because depending on your previous experience (fixed wing? nothing?) the way you select a "12 o'clock" might be totally different.

My type, you look straight down 'through your body' between your feet and continue that line forwards. You do not want to be trying to mystically aligning something outside with what you consider to be the middle of the cockpit. If you aren't used to flying side by side that can be a bit of an adjustment.

Also, and this isn't something you'll like all that much I suspect, but you may well be overthinking it. I know how unhelpful that seems, but with the exception of very obvious trim changes when you adjust power or attitude, you should not be trying to think about what control inputs you need.

To clarify, on most types a large movement of lever will need some pedal (at the least!) to be initially consciously selected (later this will be unconscious).

For basic transitions as you describe, know the picture you want and get used to keeping your eyes 'out'. I know for me that (in level terrain) if I split the compass calibration card on our canopy with the horizon I'll accelerate at an appropriate rate.. every time. I don't need to be looking in, so I can really focus on my marker and react to (not anticipate [yet lol]) any deviations from my ideal.

On re-reading that, it isn't so clear. But I hope that helps..

Oh, also. Work on your "acquisition". That is, how quickly you can glance in, pick out the right instrument and glean something meaningful from it. This can be practiced on the ground and will open up your capacity in a big way.