They sell textured paint and rollers with designs. It could be as simple as rolling the paint on. They also sell textured spray paint if you wanted to go that route.
Here is how I added a textured feature wall in my bedroom: https://thehoneycombhome.com/shiplap-accent-wall-the-easy-way/
You can also buy the texture and mix it in your paint to the consistency you want it.
I hope this helps! https://www.pinterest.com/pin/81205599516846072/