Problem selection:
Select problems easy enough that you can isolate the positions one-handed. This will get hard quickly as holds become directional and footholds get worse or scarce. Start with climbs that have mostly down-pulling holds and plenty of feet.
This is usually a warmup drill, so select problems accordingly.
Focus:
The idea is to find a stable position with each handhold before moving the other hand. While you do not need to fully rest in each position, finding the most stable base you can is an important part of the drill. The cadence is like this:
1) Move your hand. Let’s say you move your left hand.
2) Move your feet to create a stable base (a nice triangle, if possible) for that new left handhold.
3) Take your right hand off and relax into the position.
4) Move your right hand to the next hold.
5) Now repeat 2-4 with your other hand.
Combination:
This is a general session and can be combined with any session. Perform after warming up and before any conditioning.