Have you noticed how many textures there are around you? They are everywhere! As a photographer it is important that I use my imagination and have foresight to see the textures around me. Not to mention, have a way to photograph them, even if it's with my phone. Textures are used all over the place in fine art photography. Really, you never know when you will need a good texture for your photograph. It's good to have a large collection of them so you don't end up using the same one(s) over and over again. Each time you go on a photo shoot, try looking around the area for textures. Get up close to things that are sitting around. Take lots of close up photos!
Here is an example:
I wanted to take a photo of my son in a particular hat. I brought him outside our house and took a couple of shots. I also happened to notice this wood pallet laying next to our trash can...
Wood always makes for good textures so I took a bunch of close up photos of each of the pieces and was able to get at least six totally different textures from the pallet.
... And here is how I used that texture with the photo of my son in his hat. (original photo, after using texture, original texture photo) It gives a little bit of extra interest to the photo. In a way, it mirrors the texturing in his hat. I might scale the opacity back just a bit since he also has a lot of texture in his jacket. I haven't completed this project yet, but for now this works for me. And, of course, that is the most important thing. Does it work for you? Photography is so subjective. We all see things so differently.
If you learn to see the textures around you and photograph them you can eventually have a large collection of them. There are people who spend a lot of money buying texture packs from other photographers online. There is no need for this if you just use your imagination and learn to see them on your own! Good luck!