In the morning, while I'm eating breakfast, I track the exercises I scheduled for that day into SP. If I've already logged them, I'm obligated to do them! I would hate to waste the time, going back in and deleting exercises I didn't do that day.
I do this with my meals too! I log in all of my planned meals and snacks while eating breakfast, that way, I have it all planned out, and know right away if I'll be under/over my requirements for the day, and can alter accordingly!