Has the person ever really enjoyed a trip they have been on? For example if they went to Las Vegas and always talks about it, then have a Vegas Party. Or if they really like James Bond have a James Bond theme.
How about doing some voluntary work as a group, maybe some grounds maintenance work at a local hospice, children's hospital, church etc. If in Britain, maybe hold/take part in a fundraising event e.g. Climbing the 3 Peaks or organise a pub crawl (in fancy dress) - you will need to contact your local council for appropriate certificates etc but this is quite easy to do. Hire a market stall for the day and sell stuff for a charity then have a nice meal somewhere afterwards. Or you could go white water rafting, go to a climbing wall, pony trekking, a spa day, hire a barge on a canal and meander the canals stopping off for a pub lunch en route. Is that lot enough to go on?
Does the retiree have any hobbies? Or plans after retirement? (e.g. Are there plans to travel? Or have a hobby like ballroom dancing?) Use that as your guide.
Hey soz I prob didn't explain the question different. We are hiring out a hall and having a normal party, but we were just wondering if there is any type of theme or anything that might make it a bit more memorable than any other party! ta