Here is a really useful element for creating images: fractals.
What are fractals? Well, here’s what Wikipedia says (among other things): “…fractal is a term used to describe geometric shapes containing detailed structure at arbitrarily small scales.”
From that comes fractal art, which “…is a form of algorithmic art created by calculating fractal objects and representing the calculation results as still digital images, animations, and media.” There’s lots more in the Wikipedia article.
If you go to Pixabay and key in “fractal,” you will be rewarded with a wealth of shapes and patterns. Some are beautiful, like the featured image. Some are weird. Many can be combined with other design elements to produce something unique, or at least make an ordinary image interesting.
Here are a couple of fractals I haven’t incorporated into anything as yet, but I couldn’t resist downloading them from Pixabay.
I upload the fractal images to Canva and use it to assemble and adjust. (Canva also includes fractals in its photo library.) I do some cropping to size and fiddle with the degree of transparency. That’s one of the nice things about Canva–you can easily layer images and change transparency to make abstract shapes like these fractals into backgrounds or nearly transparent foregrounds.
A word of warning, though: messing around with images can eat up a lot of time.