>>Be healthy.
This - obviously a lot of things are out of our control, but it is also absolutely true that the vast, vast majority of health problems Americans have are all self-inflicted by decades of poor diet and lifestyle - as an individual, if you are concerned about the kind of care you are going to get when you need it, the very best and easiest thing you can do, is take as many actions as you can to avoid needing it.
You can't control everything, but you can do your part to ensure a healthy life - if only for selfish reasons (i.e. that won't fix the healthcare problems in the country, but it will minimize your own need for it).