Choose a watermark type: text, logo, or signature
Open your photo in an editing app or watermark tool
Add the watermark layer to the image
Place the watermark where you want it
Adjust the size of the watermark
Set the opacity so it is visible but not distracting
Choose a font, color, or logo style if needed
Repeat the watermark on multiple photos if required
Save the watermarked image as a new file
Export in the desired format and quality