Get too happy down the gears on anything but a 2-stroke or a 4 with a real slipper clutch (inspect and rebuild almost every 2 weeks). Then throw in being leaned over so far you're dragging bits on a surface street not a swept clean and predicatable track and the result will be you seeing ground, sky, ground, sky, ground, sky, and so on. Same thing snapping a quick upshift while you're grinding hard parts
If you find yourself in a spot where you're in a long curve and it's time to shift then get used to pushing the bike up while you move your body further down. This isn't dragging a knee or any other 10/10ths MotoGp technique, this is simply positioning the bike so you can find an extra shift and then moving back to your normal position after.