I wrote a plan for my funeral when I was in my early 30s - partly because I lost a close friend at that age which reminded me that we don't all necessarily make it to threescore and ten and partly because my grandmother worked herself into such a state worrying what my grandfather 'would have wanted'. I get it out and update it every 5 years or so, but at the top, I've written that these are just my suggestions and whoever is left behind is free to totally ignore if he/she wishes!
I'm obviously an odd one out here, because I find funerals helpful although painful. I always struggle to accept someone has gone, and somehow seeing the coffin makes it sink in. Also, you often find out things at the funeral that you wouldn't otherwise have known about someone - we asked a young man from my dad's church to do a reading at the service, and just before he started reading, he said 'I hope you don't mind if I share my own memory' and spoke for a few minutes about how much dad had helped and encouraged him when he was going through a really tough time and how he would never forget the support & advice dad had given him - we had no idea dad had been so significant in his life & it was something we would probably never have found out without the funeral.
For my dad's funeral, we had the cremation first followed by a service of thanksgiving. A few people were shocked that we did it the 'wrong way round', but I felt it was so much better, as we got the really horrible part out of the way first and could then focus on the good memories. It also felt much less disjointed moving straight from the service into the tea & nibbles part, instead of having people hanging round waiting for close family to come back from the crematorium/graveyard. I've been to a few funerals since then that had it that way round, so obviously we can't be the only ones who think that way.
I hated the 'social' part after, but that was mostly because I got stuck talking to a load of people who didn't know me or my dad that well and just wanted to talk about themselves & their own bereavements - if I could have spent the time with just our old family friends, it would have been more helpful.
I can understand finding funerals pointless if they are full of people who weren't that connected to the person in their lifetime, but most of the ones I've been to have been full of people who genuinely cared. I had an 'adopted' auntie (no relation, but she was my grandma's best friend, so I always called her auntie) who died at 93, and I found it incredibly moving to go to a service with over 100 people of all ages gathering together to celebrate her life.