At The Park

I love the park and I would recommend that you use the national/private parks as often as you can. It's free and all you need is to spare a bit of time to drive there/walk there and be wild.
Don't feel concious that just because you are an adult, you cannot play with your kids. At least for me I don't feel ashamed. Recommend:

1. sing to you kids when you swing them. Nursery rhymes, songs which you think they like. It's soothing to swing on the swing esp for ASD children, they love it. There are a few type of swings which you could use - some are conventional type with a tire. That's great for flexibility to stand on it or a group swing together.

2. Use the slides and tunnels. Go through the tunnels with your kids....of course not to forget size does matter when it comes to this event! Don't get stuck!
3. Play peek a boo hiding in the tunnels.
4. Climb on monkey bars: Nb: Becareful. One can break an arm doing that!
5. Jog/walk around the park. Get your child to observe and listen to the nature's sound like crickets, birds. Don't forget your mosquitoe repellent!
5.Bring along balls, rackets. You can have a bit of social games with them.

You see these are all free and just at your door step. You don't need to pay money to go to special centres to do sensory workout. Unless of course you kids have other problems, than I would advice to seek an Occupational Therapists help.