he used to sleep better but not as much nowadays
In my opinion exhaust ur child physically as much as u can - like make her ride a bike, play chase or any game that invovles running in a safe area, hold hands and jump.
Weighted blankets work really well for lots of kiddos, have you tried that yet? Do you keep track of how he sleeps and compare it to what happens prior to bedtime, what he's eaten that day/evening, whether he watches tv or not before bed, etc? A lot of time you can discover some really interested trends or behavioral correlations by looking at this type of information on an ongoing basis.
We like to use routines around here. Around 7 p.m. we turn off all electronics(iPad, video games, t.v, etc.) And the children have 45 minutes of "quiet time". They tend to read, play with stickers, draw pictures, play with stuffed animals, etc. Then about 8 p.m. they are expected to brush teeth, bathe and get dressed for bed. (This took time to master but they can do it now). Each gets to choose a book with mom or dad, a short song, prayer and lights out. This happens every night. If they come out we lead them back. They are older (4 and 6) and earn stamps for staying in bed every night and redeem a special activity when they are ready to. Can be extra time on an iPad or staying up a few minutes to talk with mom or dad. They seem to like it :)
We turn off the television because she loves Mickey Mouse Clubhouse. I have down time for about 20 to 30 minutes before bed. That seems to help on most nights. She does toss and turn and wakes up at least once a night. We are very new to this because she was just recently diagnosed. Our daughter is 2 with ASD. I have been told that if they have reflux this can disrupt sleep. Wish I could help more.