Every chance I get.
Don't put me in for sainthood...
I am proud to be a member of a volunteer team at a local ANG unit's Family Resource Group. They host 3 or 4 events a year. For the Christmas event, I helped pick up and sort donated toys into gift bags. I dressed up as an Elf and helped Santa hand out gifts.
My personal time expenditure was very small, but the thanks I get is HUGE. The unit Commander and his wife are very nice folks and give me a hug and a big smile whenever I see them around town.
I would encourage all members to see what they can do...it does not take a lot of time to say TY to a uniformed service member or help out their families.