These skills are not difficult to learn, it's not 'high order' thinking, but it does need to be learned and practiced in advance of 'things not going according to plan'!
Even on a single pitch, easily accessible crag, a few rope tricks can go a long way to speeding up a crag evacuation and getting the climber into a comfortable place. On a multi-pitch mountain crag or sea cliff, these rope tricks are vital.
Also, a weekend at the crag playing with ropes can actually be a lot of fun, just as much fun as climbing.
We started simple, I was told many years ago by a well known British Mountain Guide (BMG) to 'keep it simple, keep it safe' and this has always stayed with me.
Look for a simple solution, can the climber be lowered to the ground, or will a really tight rope help them over a tricky move? These may solve the problem before it is a problem!
Some of the areas covered were:
Tying off the belay device
Use releasable systems
Escape from the belay system
Unassisted hoist (in and out of the belay system
Counterbalance abseil to an injured climber
Lowering passed a knot
Abseiling passed a knot
Stacked abseil systems (problem avoidance)
Abseiling without a belay device
Ascending a rope - to help a stuck / injured climber
Improvised chest harness
Thanks to Miguel, Mila, and Kim for making the weekend such a lot of fun