This may sound a bit strange.
I have been collecting magazine cut-outs, catalogue pages or print-outs from the net. They are photos which interest me and which I think there is something I could learn from them e.g. the composition, lighting techniques or concepts etc.
I put them together in a 100-page clear sheets in a folder. Everytime I go to the toilet I drag it along to have a flip.
A most productive learning lesson in 10-15 minutes. I guess as something is coming out of your body, there is room to add in some visual stimulus.