This may be disgusting... but it is what we sometimes do...
Put the leftover oatmeal from breakfast in a plastic bag. Begin adding whatever you found at the bulk foods section, salty, sweet, whatever.... raisins, figs, peanuts, Asian rice crackers, wasabi green peas, peanut butter pretzels, gummy bears, craisins, dried pineapple, puffed rice, granola...
Add a banana or two and close it with a twist tie.
This is the best part.... Begin Smashing. It brings out the inner ten-year-old in all of us. Mix it up until it becomes a deliciously disgusting gloppy mixture.
Lots of energy. Salty sweet to replace the lost sodium. Different every day.