Meta descriptions are almost more important than the content itself. If someone reads your meta and decides they don't want to visit the article or printable because of what you said, they will likely not visit the article. What is the point of writing an article if no one is going to read it???
I usually have "How to" articles, so I recommend using words like Learn or Discover at the beginning of the meta description so that you can get those how-to words in there properly.
Example: Keyword - how to eat an apple. Meta Beginning - Learn how to eat an apple...
This article NAILS the main points that you need to know to write a meta description.
This is another great article to check out on how to write meta descriptions.
Remember, the meta description is what will show up under the title in Google. It's like an advertisement for the article. You want to use as many keywords as you can in there so people realize that you have something valuable to tell them and to come up more often on page one of Google's SERP!
Hope this helps! <3