Be very descriptive, but try not to use so many run on sentences or go on and on about one thing as to keep your readers attention. Also, try being descriptive of the important details, such as characters, important events, places, explanations. The five senses are important in description, especially the way something appears. Try to use description only when necessary to also give the reader a chance to visualize something without trying to think too much about unneccesary topics. Also another way to describe is a characters point of view, which if you do that, can vary on the characters personality. Observant characters might describe more than needed and non observant characters can describe less. Other characters might perceive things in a certain way but by the way it’s described, the reader is able to see the truth. Also illustrations could help if your vision of your story requires much detail that can’t be fit into words. Different perspectives could also help so the reader has a feel of what you’re trying to convey and have different characters perspectives to se how the story influenced each of them. Even just focusing on minor characters as well as main characters if this is from a narrorators perspective to see the type of environment the story is in can help the reader visualize the scenario.
Hope this helped and good luck with your writing!