Update! Click here (Grid, Guides, and Ruler Shortcuts in Photoshop CC) to discover my favorite tips related to Grids, Guides, and Rulers in Photoshop CC.
The ability to quickly add multiple guides in Photoshop has arrived! Access this new feature and customize the options by selecting View > New Guide Layout. Not only can you enter the number of Columns and Rows that you need, but you can also choose the Width or Height, Gutter, Margins and whether or not to Center the Columns. To reuse the guides in multiple images, save the New Guide Layout options as a preset using the Preset drop-down menu. You can also choose to Clear Existing Guides if needed. Here are some examples of the guides you can create.
In addition, you can create guides based on a shape (View > New Guide from Shape). And you’re not limited to only Shape layers, you can create Guides from Type layers and pixel based layers! As you can see from the examples below, the Guides are created based on the bounding box around the contents of the layer
These two new features are going to save me a significant amount of time!