Using descriptive words like adjectives and adverbs is one of the simplest but least engaging strategies in descriptive writing. Adjectives tend to slow the pace of writing and are usually single-function words, minimizing a writer's ability to accomplish multiple tasks like adding information and increasing reader engagement at the same time. When using descriptive words, do your best to choose strategic words that develop a specific, evocative and nontrivial aspect of what you are describing.
A central strategy used in descriptive writing is analogy, or a comparison between what you are describing and something else the reader is likely to be familiar with. For example, you may describe a tree's branches as "outstretched like a joyful child's arms." When forming an analogy, choose one literal aspect that the two parts share, like the outstretched position, and pick an analogy that has the emotional connotations you want to communicate. In this case the analogy creates positive associations; for a scary feel, you could write something like, "reaching out like a strangler about to strike."
While an analogy generally links two objects, you can also create a link with your reader's experiences in order to help her understand what you are describing. Whatever you are describing has some relation to common human experiences that most people will understand. Painting "emotional word pictures" draws on these commonalities and is especially useful for cutting deeper than physical descriptions can to evoke emotional experiences. For example, you may describe the desperate isolation of a divorce in progress by writing that it feels like being lost deep in a cave with only a dying candle for light.
Where adjectives and adverbs are weak descriptive words, well-chosen verbs are strong. They allow you to combine action and description, which keeps interest high by layering description with progress instead of stopping the action for an information dump. It is usually possible to replace adjectives and adverbs with descriptive action words if you creatively reword the sentence. For example, instead of writing, "The dirt road was mottled with shadows and yellow sunlight," you can describe the same image actively by writing "Sunlight slipped between the leaves to decorate the road under our feet."