Personal projects keep the creative mind and motivational drive alive and fresh.
The images may look very easy to accomplish but the reality is a lot of planning, luck and experience.
I suppose you can say we practice all this on personal projects where we are the client. It's a chance to try new techniques or shoot in a way that many clients may initially think is too arty or not commercially sound until they see the results.
Interestingly we have found that by experimenting and giving some space for a more creative flow on personal projects, many of the ideas are picked up as work we are asked to replicate for brand campaigns.