coping strategies are generally learned through behavior modification and or behavior therapy. It can be a lot of trial and error to figure out what works for each person.
For example, my older son has to pace during school. This is one of his coping strategies for dealing with both anxiety and hyperactivity.
My youngest son, on the other hand, needs to have behavior modeled to him and one of the better coping strategies has been to place him with a group of girls (and he's 7 and already girl crazy). This is because they tend to be chattier (like him), less prone to outbursts (unlike him), less likely to get physical (unlike him) and he has a thing against hitting girls (and one of his major impulse control areas has been hitting).
Other things have focused on moving from larger more exaggerated things to smaller ones. For example, my oldest son used to scream loudly when he was angry. We moved from that to growling. We moved from growling to foot stomping, we moved from foot stomping to crossing his arms (like hugging himself) and making faces (now we have devolved to the preteen/teen stomping up the stairs and slamming the door with a your so mean and never listen to me thrown in).
So if you have a fidgetier, your looking to have them move from openly fidgeting to maybe hand or foot tapping or pencil twirling etc (I find typing to generally removes all the fidgets out of all of us because those fingers fidget like crazy over those keys!)