The easiest way to begin drawing from life is to use a model. Draw what is directly in front of you. This can be a person, an object, or a landscape. Drawing directly from something you can observe will result in the greatest improvement in your skills. Try to work as quickly as you can. This will teach your brain to take in the most important information quickly and efficiently. Note basic shapes and proportions before moving on to details. This will keep you from having to adjust if your model moves. . If a live model is unavailable, you are worried about the model moving too much, or simply don't have the time to devote to a live model drawing, you can draw instead from a photograph. This is not as effective a learning tool but produces similar results in terms of a final drawing. If you want to draw something photo-realistic but lack proper skills, this will be the easiest method since you will be able to take in minute details at your own pace. . Though you will not learn as much, you can simply create a realistic image from your imagination. To be truly realistic, you will need to have an excellent understanding of light and shadow, as well as proportion, form, and fold physics.

How would you rephrase that briefly using Chinese?
找一个模特。 临摹一张照片。 画出你想象出来的东西。