There are some parades here and there because of the large Irish community in DC, but other than that I would just be at home and sleep or look at St. Pat's day memes. There's also the (in)famous McDonald's shamrock shake, but I have yet to try it.
I remember I used to go searching for four leaf clovers for hours and hours--- whenever I found one I'd eat it to "digest the luck". Oh, you idiotic child...
The McDonald's shamrock shakes have a light minty taste (like vanilla with mint) but the McD's shakes are a little on the think side for me. I like thick milkshakes but I like them thick because of the ice cream and not the thickener.
I tried their shamrock latte as well which was mint flavored mocha...ok but not going out of my way for them.