I too would recommend using sand bags from the bench. You shooting an AK, if you are using 30rd mags you'll want to stack those sandbags up pretty high or get some 20rd mags.
The idea is you don't want to mono-pod / rest the rifle on the magazine. You want the forearm of the rifle to rest on the sandbags. The sandbags reduce your movement of the rifle.
I think others here have covered trigger & sight picture pretty well. The goal is to do the same thing for every single shot = consistency & repeatability.
Just re-iterate a point from Unclenick's post - breathing and breath control.
The Army taught us to hold our breath on the exhale. There is a natural pause in your breathing between the exhale and inhale (2 to 4 seconds).
The goal is to pull the trigger within that time period. Normal breathing causes your sight picture to move up and down. Briefly holding your breath - (pausing at the end of an exhale) helps you stop all movement of your body that affect your sight picture.
When I'm really shooting for accuracy at the bench - I take my time and count my breaths between shots. The goal is perfection.
Don't get out of breath. Don't overdue it.
One more trick regarding trigger pull from the Army. We would practice dry firing from the prone unsupported position. We focus our sights on a spot ong the wall then have a buddy balance a quarter on top the barrel near the muzzle. The goal was to pull the trigger without the quarter falling off the barrel and keeping the sights focused on the spot on the wall. (Empty rifle - obviously)
Lastly when shooting / sighting in a new rifle (AR, AK, M1A, etc). I shoot for a tight group (3 to 5 rounds in a group) and the adjust the sights to move that group where I want it on the target.