The way to preserve our body is to prevent bacterial growth and the degradation of tissue. There are a few things that we know of that will preserve humans:
-Chemicals. Like formaldehyde, these are usually highly toxic to living things, but they do a fairly good job at preserving dead tissue. They don't perfectly preserve everything, though. Things like hair and parts of the eyes will not survive.
-Cold. Cold prevents things from decaying, so cryogenic storage is a great way to preserve a body. However, this is very expensive, and it definitely depends on the cryogenic company staying in business. You could go die somewhere extremely cold, but you will most likely be out of nature and if animals find you, then the cold is not going to help.
-Peat bog. Because of the acidity and the soil of bogs, bacteria cannot grow, so decomposition is nearly halted and anything buried in a bog will be preserved for a very, very long time.
-Dedication. Bacteria need somewhere moist to grow, so if you were to dry yourself out, i.e. turn yourself into jerky, you could be preserved for a very long time.
Unfortunately, none of these are really methods you could do by yourself, but these are the ways that we most often have recovered remains from people or animals that have died a very long time ago.
I think the idea of people thousands of years in the future being able to see my corpse still intact is a cool idea and I'm paranoid about wasting my life and not leaving a legacy long enough for the sands of time to make all this remaining on Earth thing worthwhile, so what method should my corpse be stored? I know bogs preserve bodies very well but they have a habit of looking all rasin-y and squished in places (and also bogs wouldn't make a pretty grave). If you can preserve gherkins in vinegar then could you preserve bodies in like a big pickling coffin? Would roses still be able to grow on top of it? This is a weird question, I'm sorry. I'm vain about if I still look pretty in death.
