Luckily, you don’t have to print out every single artwork of yours, hang it on wall, in different settings, and photograph it from different angles to make your art prints look good for sale online.
There are way easier options.
If you are a traditional artist, you’ll only need to have one good, well-lit photo of your painting (from a straight angle). As a digital artist, saving your digital creation for web is sufficient.
With that done, all you need to do is get a mock-up that looks good with your artwork. Decide in what kind of setting you’d like to display your work—I’m sure you’ll find a nice, customizable room mock-up for art print size you’d like to display.
Most mock-ups come as PSD files that you can edit in Photoshop or any other app capable of handling PSD files (→ TOP 4 FREE Alternatives To Photoshop). To put your own artwork into the premade scene, all you need to do is double-click on the Smart Object layer, paste your own image, hit save—and there you are!
Of course, you can also change lighting, hue, shadows, etc. in Photoshop. Everything can be customized to your liking.
In case the mock-up is meant to display your art print from an angle, you don’t need to worry about the perspective, because it will be adjusted automatically. That’s how easy it is.