I find that breaking any task into chunks helps. Say you were doing the dishes, which I really need to do, you could consider the whole task or you could break it into chunks such as fill the sink with soapy water. I find tasks become easier this way. When I am really out of it, I write out all the steps and cross them off as I've completed them. I use it for my depression, but I would think it would work for ADHD too.