Below are some of things to consider. The celebrant you choose will help you create the ceremony that is right for you, your family and your friends.
Where might you hold the funeral ceremony? In a church, the crematorium ceremony hall, at the graveside, in a community hall, at home, in the garden, in a marquee or yurt, in a function room (with separate access), on a boat? You can hold a funeral ceremony almost anywhere with the permission of the owner of the land or building.
Would you prefer to have a ceremony for everyone with the coffin present, a private cremation or burial, or a burial or cremation first and a memorial ceremony (perhaps with the ashes present)?
Would any family or friends wish to be involved in bearing or transporting the coffin to the funeral, decorating the coffin or ceremony space, or preparing food and drink for a gathering afterwards?
What type of ceremony would feel right? A celebration of life, a religious service, a spiritual or non-religious service, something in between that reflects the particular views of the person? In which case do you want an independent celebrant who will reflect the views of the person, a religious minister or friend or family to take the ceremony?
You can choose your own content, music and words for the ceremony. Your choices will be fine as long as they reflect the character and beliefs of the person who has died. Not everything needs to be funereal.