I did this for my kids a few years ago when DS was 8 & DD 67, they are 15 & 12 now!. I gave them the their first clues (both had there own clues and items to find) which lead them around the house 'gathering' there next clue and items as they went. The things that were hidden were all holiday themed and the items they had to collect were little travel bags, sandals, swim suits etc. The last 'clue' was a joint one that there previous clues lead them both too. The final piece of the puzzle was a letter I had done using pictures and they had to fill in the blanks, it was kind of like a poem with the last line to tell them to pack their cases as we were off. I had pictures of planes, cars, houses to help them solve the riddles.
In fact I just found the file (from 2008) with it all laid out, I have tried to attach it so you could have a look, no idea if it will work or not! - forgot that I could be creative when I wanted to be. You will see from the last page of the attachment that this was also a surprise to my husband!
