Not a great fan of being bounced around - my worst experience was on a flight from Asuncion to Buenos Aries on a Aerolineas 737. Flight was fine up until we started the descent into thick very black and lightning filled clouds. Gentle(ish) bumps / movements but then one violent drop that set the scene for the remainder of the flight. The seat in front hit my leg with such force it tore a hole in my trousers and even managed to cut my leg (which i did not notice until we landed) One of our group's seatbelt had come undone and he was hanging on to arms very tightly. Loose stuff was being tossed about and I remember seeing a passengers' briefcase 'hover' for what seemed like an age but was probably only a couple of seconds. BA at the time (1996) was an overhead join as it was possible to see Ezeiza below us. The winds were pretty strong as I remember looking out of my window (rhs behind wing) and being lined up with the runway. Touchdown was positive but have had worse in much better conditions although we did weave a bit as we slowed. (spontaneous applause all round) About 30 mins after we arrived a World Md11 landed (with an autothrottle problem i think) and departed the end of the runway at low speed - no injuries / damage but it did close the airport for a few hours.
Agree with other posters who say as soon as food / drink is served that is when the turbulence starts.