Can't speak from my own parenting experience yet, as ds is only 13 months.
But when I started asking my mum and dad about Santa, they always seemed to have an answer for me.
In one house, we didn't have a chimney, so Santa came in through the loft hatch. That's where we had to leave his milk and biscuits and a carrot for Rudolph (all always gone by morning).
One year my dad (I know this now ) hid round the back of our house and rattled some jingle bells at about 4 in the morning. My mum called us outside claiming she could see the sleigh flying off our roof.
Another year, my dad climbed out of the velux window and stamped reindeer footprints in the snow on our roof.
Santa never made our christmas presents in his workshop, the elves couldn't make My Little Ponies , but my mum and dad would have a look round the shops for him and tell him where to go to get the right presents (he was so busy you see).
We posted our letters to Santa by sending them up my gran and grampa's chimney (a real tradition for years).
The most convincing Christmas for me, was when my grandparents stayed with us and so my brother, m and d were all sleeping in the same room. Kids at school had told me that year that your parents were Santa and he wasn't real, so I stayed awake and watched my m and d until about 4/5 in the morning then checked outside the door to see our full stockings! Of course it didnt' occur to me for years that my gran was santa that night, but it shut the kids up at school for a while. Ahhh innocence.