From Odeedoh I found this blog by Rachel Denbow, who illustrates how to make this lovely felt calendar:
It is quite simple, but I like simple! I also like that the gifts aren't THINGS necessarily, but activities to do together. And the colours are lovely.
Along the same lines is this one from Linaloo (I also quite like her blog):
In response to the question of whether it was worth it to go to the trouble to make one, she said she overheard her daughter telling a friend "My mom MADE mine, it is way cooler." :)
For something a little more out of the ordinary, I REALLY love this one by Elsie Marley, who includes a whole tutorial on her blog.
Then there is this one from Life With Little Ones. She uses little envelopes and arranges them differently each year:
There are some labels on etsy that would be fun to use for a project like this:
I also loved my friend Kendra's craft calendar - a blank calendar drawn on a piece of bristol board. Every day Alex gets to make a craft to be glued on to the space for that day. Send a pic Kenj and I will put it up! Do you keep them from year to year?