Generally the worst turbulance you will ever encounter on a scheduled flight is moderate. The minute the crew report "severe" turbulance the a/c becomes due for an inspection. (in many cases)
Aircrews usually monitor the frequency for "ride reports" from a/c ahead of them and can usually avoid the worst.
Of course CAT (Clear Air Turbulance) is unpredictable, but if you were to have an encounter with something severe, I'm sure we'd all be reading about it.
My suggestion, relax and enjoy the ride. They used to call this an "E" ticket, from the old way of doing business at Disneyworld.