This could be summer dresses,
Everyone wearing a splash of their favourite colour.
Give people something to remember them by as they leave. This could be a sweet because "he always gave everyone a sweet as he got on the bus." A packet of bird seed, a packet of seeds, An ice cream.
A single flower or petals can be placed in the grave at the end of the service or at a crematorium it could be placed on the coffin as each person leaves.
A member of the family could play a reflective piece during the service or a professional musician could be arranged.
This could be a professional, a church choir
The Guard of Honour can be traditional and made up of uniformed individuals, e.g. Army, Police etc. or unusual:
Cricketers in white, Cyclist etc.
The cortege can be made by his friends either driving/riding their favourite transport.
Just a few ideas to make the day special