This tip is to save time when creating a group of squares or any type of grid in Illustrator. This is a good trick for making easy grids in Illustrator. For our purposes, I am creating a 300px by 300px square and it is filled with purple. You can make yours any color that you want. Now, grab the rectangular grid tool, which is found under the line segment tool. click the artboard with the rectangular grid tool in order to bring up a menu. With the menu up, you can decide on the size of the overall grid. Since our square is 300px by 300px, make it the same size. Then, you can decide the number of dividers for the squares.
The skew function makes each square progressively larger or smaller depending on the values that you dial in. The fill grid check box fills the center squares of the grid with the fill color that is selected when the menu is brought up. You can always change this at any time. The stroke isn’t filled, but you can choose a stroke color and make the grid show up as any color that you want. Also, if you want a thick grid os a lot a space between each square in the grid, then all you have to do is bump up the stroke value.
This grid feature is a great feature that you could make here in Illustrator, and then copy it and paste it into Photoshop as a smart object or paths and create some interesting effects with, such as overlaying it on top of a photo for a modular look. This is much faster than creating each individual line, using the alignment panel to distribute the lines evenly, and so on. To me this is a very handy tool with many good uses.