So here are a few things that we are doing to help in this area. For starters, he has qualified for occupational therapy at school. I'm very thankful for this intervention and we know that it will make a difference.
At home, we have started using PenAgain's Twist and Write pencils. We love these pencils! They are also available at amazon. This pencil does not address the bigger issue Ben has with hand eye coordination when writing. (I'm sure there isn't a pencil in the world that could do that.) But it does eliminate the confusion in regards to grip. It's also small enough that his hand doesn't get tired from holding the longer pencil. There are two built in erasers on the handles so it works just perfectly for him.
One last tip I have for working on letter formation is an app called Letter School. This app is definitely worth the small price for your mobile device. It's a favorite around here for sure! In the settings, you can even choose HWT as the model so it works perfectly as a reinforcement.
The bigger issue is getting his hand to do what his mind wants him to do. I'm still looking for more ideas and would love to hear suggestions in the comments section.