I need to up my Mother's Day game! I've noticed that a lot of families will do breakfast in bed for mom, or will take Mom out for a nice brunch (or meet up with all the moms in the family for brunch). Families will also sometimes do a fun Mom-centric activity in the afternoon, like a picnic or a trip to the beach or museum.
As for me, I usually just write an email to my mom and a card for my wife. And we'll usually try and do something fun in the afternoon.
What's the typical Mother's Day like in your house?