Applies to many things, in life as well as profession:
- Untested code isn't done.
- Unreleased code isn't done.
- Undocumented code isn't done.
- Set many, small, specific goals.
- Simplicity gives you more options than complexity.
- Do something every day. Finish something every week.
- One feature finished is better than ten features planned.
I've kept this bit of wisdom for years. Alas, without retaining source info. My apologies to the author. If it's yours, let me know so you can be properly cited. Thank you!