Hi Hudsmom, good to meet you here.
How old is your son? Getting to sleep can be tricky. [edited later to add: OK, I just read your other msg that says your son is 12]

Try a longer wind-down time before it's actually time for sleeping. If a child has been busy in school all day and busy doing other activities after school, it would be common to have a flurry of tics when it's time to lie in bed to go to sleep.

Dim the lights earlier. No video games or tv close to bedtime. Have that relaxing bath, but also allow some extra time for the tics to subside.

If a child has been holding in tics all day in class then they will come out later. If it's apparent that is happening then it's a good idea to speak to his teacher to see if there are some practical measures that would help him release more tics throughout the day so it's not like a volcano of tics the moment he gets home.

If possible have him doing some physical exercize after school. Running, playing etc.. Set up a routine for every evening/night. Dim the lights. Keep the bedroom just for sleep and rest.