Deep in the best convos about productivity is a great link by Bakadesuyo about Jerry Seinfeld:

He told me to get a big wall calendar that has a whole year on one page and hang it on a prominent wall. The next step was to get a big red magic marker.

He said for each day that I do my task of writing, I get to put a big red X over that day. "After a few days you'll have a chain. Just keep at it and the chain will grow longer every day. You'll like seeing that chain, especially when you get a few weeks under your belt. Your only job next is to not break the chain."

I like to use smiley faces instead of X's, but the point is a great one: Daily action builds habits.

Conversely, skipping one day makes it easier to skip the next.

So don't skip.

So true.

I can't tell you how many times I've seen this example with me and working out at the gym. It's sooooo easy to hit the gym once I've motivated myself to turn it into a habit. It doesn't matter how busy my day is, I take extra care in pushing myself towards getting a quick workout in, and it's not much effort to do it. If I miss a few days in a row, I can find any little excuse to make sure I don't go back... And motivating myself to get back into the habit is as hard as lifting a Buick over my head :)