Whether you are using Photoshop, Affinity Photo, Photopea or any art or photo editing software, the goal is to create stunning works of art that you can hang in your house or sell online without spending a ton of time of them. Here's a quick technique to create visually arresting space images, featuring astronauts, NASA elements, planets, starry backgrounds and all sorts of great astronomy components. The nice thing about space images is that the resources are almost always in the public domain and there are thousands of photos to use as your base images. I also have a bonus image regarding patterns.
Here's where you can grab free images: