To create watermarks using Photoshop, I first imported my desired image or logo onto a new layer. I then adjusted its opacity to a level that would make it visible but not overpowering. Next, I positioned the watermark in a corner or along the edge of the image to ensure it doesn't distract from the main subject. Lastly, I applied a layer style, such as a stroke or drop shadow, to make the watermark stand out and prevent it from being easily removed or cropped out.