If you can get free ink by writing "How To" articles, you want to be sure to make the most of the space they give you. Give the article some meat, and a plug for your company, even if it is only 500 words.
For example, here is something that might be written by a veterinarian about how to keep pets safe during the summer:

 Keep water dishes filled. If your dog or cat is allowed outdoors, it's a good idea to provide water dishes inside and outside.
 Open your car windows several inches. If you must leave a dog or cat in your car while you run into a store, make sure you are gone for no longer than 5 minutes. On sweltering days, parked cars can be deadly, even when the windows are left open.
 Keep animals inside the car. Don't let your dog or cat ride with its head sticking out the window. This can cause ear infections. The animal also could be thrown out the window if you hit a bump or make a quick turn.
 Exercise animals with caution. Don't force dogs to run or go for long walks during hot weather.

Longer articles offer more leeway. But to learn more about how to make the most of your article specifications see Special Report #6 "How to Write "How To" Articles That Position You as an EXPERT"