Short answer: choose a source image you would already want to use as the first frame, describe one coherent motion idea, select the available settings in the app, then keep the finished clip with its source for later reuse.
Choose a source that has room to move
Images with clear subjects, depth, readable lighting, and a single central action generally make better starting points than a crowded scene. Decide what should move and what should stay stable before generating.
Write the motion prompt in layers
Describe the primary subject movement first. Then add camera movement, environmental motion, and a final constraint. For example: “The subject turns toward the window; the camera makes a slow push in; soft rain moves outside; keep the face stable.”
Use settings intentionally
Duration, resolution, aspect ratio, and the selected video option affect the request. Motion16 shows currently available settings in the composer so you can confirm them before sending.
Read status honestly
Video work may queue or render before an output is available. Clear status is more helpful than a misleading percentage, so verify whether the project is queued, processing, completed, canceled, or needs attention.
Continue from the completed result
Keep the source image and video in the same project. That lets you reuse the prompt, create a related image, or start another video pass without rebuilding the scene description.