This is actually something I need to work on too. I can get lucid, it's just staying there. I shout out stuff like "Increase lucidity!" and make sure I stabilise the dream before I take off exploring. Rubbing your hands also helps. Try and engross yourself in your senses. Smell things, touch things, but remind yourself that you are dreaming. It helps me.

But I find that the better I get at getting lucid, my dreams naturally get longer and improve in clarity

I heard that although spinning is good, most of the time it causes you to change dream scenes.