With DMOZ an Open Directory project closed as of March 17, 2017, Google no longer uses their listings as one of the options for generating search snippets. With that in mind, good meta description is even more important. So here are a few pointers on how to make a good meta description:

1. Don’t forget about it, without it google has no choice but to use portions of page content for their search snippet.
2. Keep it short. Although there is no actual limit on how long the meta description can be, meta description exceeding on average 160 characters will be truncated.
3. Make it unique. Do not use the same meta description across multiple pages. Each page on your website should be unique and so should the meta description.
4. Stay on topic. Good meta description can increase click through rates so make it informative and to the point.

Note that with Google’s new mobile-first indexing the same principles apply for mobile pages. If you have a separate mobile site, make sure that the meta description is correctly included on all mobile pages.

Google still reserves the right to choose between page content and meta description for their search snippet generation. The one thing you can do is to specify nosnippet robot directive to prevent snippet generation all together. For more details on search snippets see latest post by Gary Illyes titled “Better Snippets for your Users”