Here in the great State of Kansas we have some lenient laws of the dead. You are allowed to bury your dead on your property, but you must check with your county to see if they allow it. It must be done within 24 hours of death. No casket required, and you must supply the State with a death certificate. Embalming is not required, as I said you have 24 hours to bury, unless you can refrigerate or place the body in a sealed container. And you do not need to use a funeral home.
So how does one go about doing such things. First off, always honor the deceased requests, as much as you can within the law. It isn't legal to smoke pot out of your buddies skull, no many how many times he made you promise that you would.
6 feet down is not the law. Most places do not have a depth standard, California, it is only 18 inches. 6 feet was the standard during the plague, in England. The thought was that at that depth, the dead wouldn't be able to pass the disease onto the living. They did not know at the time that it was fleas that were the problem. Your grave should be deep enough to keep scavengers away from the remains, 30 inches at least.
I was unable to find any info for the State on a Pyre Cremation. With something like that, be prepared to stay with your dead for several hours, to a few days. Make sure the fire stays very hot, and doesn't spread to your land.
I wouldn't bother taking the time to mummify your dead, unless it is winter and your can't or don't have anything else to do.