I visited a nice clearing in the forest next to my local park, this exercise required a set of consecutive drawings that was taken from the same spot but facing four different directions.
These sketches were to be completed within 15 minutes, I set up a timer and stuck to it. Having a time limit is a challenge but also forced some productive direction in the way I needed to approach the task.
One of these things was to work over the whole drawing ensuring my composition was mapped down and working as it should be. Another was extracting the minimal information to make the drawing successful.
I think I would like to incorporate these time limitations into my drawing flow, they would work really well at the initial experimental and discovery stages, allowing me to quickly feel my way through what works best and not so well.