If you have an extremely weak stomach then don't try this. Lay on your bed on your stomach. Lift your head, face forward, and begin moving your whole head in big horizontal figure eights (like an infinity symbol with the loops left and right) about one per second (I like to say 'One Mississippi') for maybe 20 seconds then stop. Crazy people may want to experiment with longer.
If you wish, you can pretend to be Snoopy, diving on the Red Baron and make machine gun noises as you hurtle Earthwards 
Try standing with your right arm straight out in front of you and stick your thumb up. Now while focusing on your thumb, begin spinning slowly in a circle. Start with only 10 if you can do that many.
Sufis use spinning to facilitate meditation...
https://en.wikipedia.org/wiki/Sufi_whirling
The Mevlevi Lodge of Dervishes in Istanbul performing the whirling meditation called SEMA. The fellow who stands on stage and does not move is the master.
Take any standing exercise where you turn from side to side, back and forth. Try the one with your arms outstretched to the sides, legs spread kind of wide. As you turn at the waist ,from left to right ,then right to left, your eyes normally follow your fingertips in the direction you are turning. now start trying to reverse the eyes to move in the opposite direction that the body is turning....It is very difficult, and many people fall over like drunks when they try it. but, if you keep it up, you will get it, as you are rewiring and opening new neurological pathways. there are many exercises you can do this with. As a class, it took us about a month to get comfortable with, doing it twice a week. The results are the ability to act and move in new ways, trusting in your movements without having to follow with your eyes, freeing them to see more of what is around you, or, to just leave the eyes out of the movement all together. without the need to "lead" the movement, the eyes can transmit more of the other info they pick up that we aren't conscious of....who knows what you will see ? don't give up!!!!!!,,,T