What are grids and guides?
Maybe you’re editing a photograph and want to make sure the horizon is completely straight. Or maybe you’re creating a graphic design and want to be sure your logo is exactly aligned with a shape on the other side of the image. Instead of just eyeballing it and hoping for the best, use grid lines and guides to precisely organize your canvas.
Photoshop grid lines slice up your canvas into numerous subdivisions that you can use to determine spacing and alignment between objects. These lines are non-printable, so they’ll never show up in your finished image.
Unlike grid lines, you can create guides and place them wherever you want. Adjust and rotate them until they’re right where you want them, and then lock them in place and use them to compose your design.
Enable snapping to make alignment even easier. Go to View › Snap to › Grid. Now when you move an object or a selection within eight pixels of a guide or grid line, it’ll snap directly to it.
How to make a grid in Photoshop.
It’s easy to create a grid and then scale it up or down until it’s the right size for what you’re trying to do. For example, to edit a family portrait and abide by the rule of thirds, make a 3x3 grid in Photoshop so you can align your image.