TL;DR: If you want to make less stress for your loved ones, you'll plan your funeral yourself.
Also I remember seeing a post on HN a while back about water cremation. I thought it was interesting.
* Leaving Earth the Greenest Way Possible: Water Cremation - YouTube || https://www.youtube.com/watch?v=7Le7rLbkFe4
(apologies if I misunderstood the question)
IMO, the best approach is to just buy a 15K to 25K life insurance policy. If you are young and healthy, it'll only cost 10 dollars a month (maybe less) and the nice thing about those is that you/your beneficiary gets the money at death (tax free in most cases) and the funds can be used for other things beside final burial expenses.
Be careful of some of the plans sold by funeral homes. They may be the beneficiary and you may not be able to move your plans to another funeral home or use left over funds for anything else, etc.