My kids are 15 and 18 now so a lot of the 'magic' feels over.
None the less, Santa still came. I still found myself staying up late on Christmas Even to put Santa gifts in front of the tree. Santa doesn't wrap in our house so at least I don't have to worry about the paper!
When the kids were little, there was no lengths I wouldn't go through in order to keep them guessing and make it magical. Santa's sleigh bells on the roof after they'd gone to bed... Santa's footprints in the house... lots of elf magic for years... a Christmas angel, etc.