I find walking quite useful and something I can do when dissociating as it doesn't require much thought. Pick a route you know and some comfy shoes though because if your anything like me you might walk for ages. I once went out in converse wandering the streets for four hours. I got completely lost and my feet blistered and started bleeding. Now I always wear comfy walking shoes and walk down to a nearby fishing lake and just walk around that a few times until I'm ready to go home. No blisters, no getting lost and I'm only 10 minutes from home so people will be able to find me easily if they get worried.