Use Guides?

Anytime you need to line things up, you can drag out horizontal or vertical guides over your image. To get to these guides, first you have to make Photoshop’s Rulers visible (press Command-R [PC: Ctrl-R]), then click-and-hold directly on the top or left-side ruler and drag out a guide, positioning it right where you want it. You can reposition them using the Move tool (V; when you move your cursor over a guide, it will change into a double-headed arrow with two lines in the middle [seen circled above]. That’s your cue that it’s ready to move). If you want to add a guide based on a measurement (for example, you know you want a vertical guide added 2" into your image or 35 pixels into it, etc.), you can have Photoshop place it exactly at that position for you: Go under the View menu and choose New Guide. In the dialog (seen in the inset above), enter the measurement you want (enter the number, then a space, then “in” for inches, or “px” for pixels, etc.), click OK, and it places it precisely for you. To delete a guide you don’t want anymore, just drag it back to the ruler where it came from. To delete all your guides at once, go up under the View menu and choose Clear Guides.