One great way to improve the design of your WordPress galleries is the JetPack plugin.
Once JetPack is installed, you can enable the "Tiled Galleries" feature. If you have a photo gallery set up, you will now get a "Tiled Mosaic" option for your galleries. This will show your images in a beautiful mosaic layout.
What's the difference between a normal photo gallery and a mosaic photo gallery?
A normal photo gallery will often have regular spacing between each image, which can leave some unsightly gaps:
On the other hand, a mosaic photo gallery will reduce the gap between each image to produce a tiled effect.
Watch the video below to see how to create mosaic galleries in WordPress: