Just found this thread and wanted to add my experience with my mother-in-law's ashes. A week or so after her cremation we met with the local vicar at the church and were taken to a little plot surrounded with roses. There the vicar produced a hideous cheap plastic urn, presumably supplied by the crem, unscrewed the lid and took out a clear plastic bag containing the ashes. She tipped them out of the bag into a hole that had been dug, said a little prayer and then looked at us expectantly. We really didn't know what was expected of us, so I picked up a bit of earth, dropped it into the hole and said, "Good-bye, old friend". The others sheepishly followed suit. The vicar went off with the empty bag and urn (for recycling?) and we all went home, feeling rather stunned at the business-like way the "ceremony" had been conducted.
My mother and father's ashes are both buried in the same tiny plot at a crematorium, although my mother died 20 years after my father. Helpful crem staff enabled this. The plot situation is measured in footsteps. The burial ground is on a hill and my instructions are 13 steps up and 1 1/2 steps across. There are no plaques displayed, so it's a bit random.
Mother's second husband, however, is elsewhere, though at the same crematorium (his children's wishes).