Usually, if you have a domineering grandmother threatening to make your name mud if you fail to live up to her expectations, you have little chance of not being motivated.
In all seriousness, I look at myself, my circumstances and/or my family's circumstances. I want to better them. That is enough of a motivation. For me, gazing into the sky or meditating/reflecting in an open place can act as a good catalyst for such self-motivation.
If it's about art or any other creative work, then I have a habit: each day, before bed, instead of counting sheep or something like that, I think of all the things I have seen or done that day. Some random image that flashes through my half-conscious mind can inspire me to create or act accordingly.