This may be more answer than was intended, but I found the question to be both important and complex ...
As some of you know, my daughter died a few summers ago and I suddenly found myself dealing with funeral preparations - something not taught in school and immensely difficult to deal with emotionally. To make matters worse, being an atheist I did not have the support structure typically provided by a Church, Mosque, or Synagogue. I was left with selecting a cemetary, purchasing a casket, deciding on the location of the service, its character, its agenda of speakers, even such things as the type of music and the presence or absence of religious symbols in the room.
After some thought, it became pretty clear that I needed to do something more than honor my daughter. I needed to honor my own grief as well as the grief of other relatives and friends. Many of these were theists (Jewish, Christian, and Hindu).
I tried to focus on simplicity while honoring those in attendance. I asked one relative to recite the Mourner's Kaddish and a friend to read the 23rd Psalm. I spoke and then offered the podium to others. Having no experience in such things, I did my best, and I think I did OK.
What I learned from the experience is how very much the funeral is for the living. As a result, I've already purchased plots for my wife and I. When I die, the sort of funeral I would like is one that places no financial burden on those left behind, yet one which helps them to deal with what lies ahead - and that needs to be largely up to them.