A few years ago I decided I would fix the issue by buying all the cards I needed for the entire year in January,
signing, address and putting a stamp on them and then putting a reminder in my calendar.That worked great until I moved, lost my calendar and had a kid.
Now I am in trouble all over again but I have found a solution ( I should say Littlest Sister found it). Jack Cards.
This is so great. You do still have to organize things a bit but after that, they take care of everything, even if postage goes up or you don't look at your personal calendar for a week or two.