Where can you get photo for the texture? Put your product on white paper. Attach your camera to a tripod. Shoot your textures at close to a 90 degree angle. Take many photos. Remove the blurred edges of the picture. Done!
For this example, I took a free photo from pxhere.com. For texture creating, you can use any bitmap editor of your choice.
Cut the left side of the image. The width can be arbitrary, but with a sufficient number of whole objects to form a pattern.
Slide the cut piece to the right edge.
Remove the non-full parts of the pattern.
Soften the edges of corns with blur tool. Add shadow. For the shadow use the dark colors of the texture. Not black.
Merge all layers to new layer. Repeat the entire process with the bottom edge.
Slide the cutted piece to the top edge. Remove incomplete grains.
Add shadow. Save texture as PNG file.
Open image in Photoshop and define pattern.
Open or create a new PSD document. Fill a new layer with a pattern. Wow! Looks good.