Hmm, interesting question. I would say social media but it’s toxic for so many other reasons. Perhaps an online virtual assistant? Or maybe charge yourself a monthly or weekly fee into some account until you complete the task? Since it’s purely for yourself, whatever act “costs” you should be enough. A friend of mine was a huge proponent of making physical lists at the beginning of each day. He would then move any uncompleted tasks to the next day’s list, and the act of physically writing it was enough for him. He insisted it be on actual paper. This guy was super accomplished so it must have done something for him.