Writing is about being clear and using descriptive words to make points, convey ideas, or describe situations, scenes, and people. That is why writers should never use the word "thing" - a thing is rarely just a thing, and writers usually mean something else like:
For example, the sentence, "The things to look for in a potential mate are honesty, sincerity, and emotional maturity," would be more descriptive if written, "The qualities to look for in a potential mate are honesty, sincerity, and emotional maturity."
If you're writing a how-to about making a birdhouse and want the reader to gather the necessary materials or equipment, instead of saying, "Collect the following things," write, "Collect the following objects." (You could also be even more specific and instruct them to gather materials and tools. )
In short, the more specific you can be without bogging down your text with confusing details, the better. "Thing" is not specific, and this word should not be used in professional, sophisticated writing except in the most literal sense. It is also appropriate in dialogue to show derision or to identify a person's ignorance.
"When was this thing made?" Roger asked his roommate, closing the hood of the rusty Ford Nova and wiping his hands on a clean towel.
"Move the thing! No . . . that other thing!" shouted Vizzini to Inigo and Fezzick. The vessel sailed in the direction of the Cliffs of Insanity, where the three villains with their hostage would shake the trail of the Man in Black.