Use a stud finder to locate the studs in the wall.
Mark the center of the studs with a pencil. Then extend the lines up and down the wall with a 4-foot level, making sure you keep the lines plumb.
Locate high spots in the floor.
Begin by placing a straight 2×4 on the floor against the wall and placing a 4-foot level on top of it. Shim the low end of the 2×4 until you get a level reading. Transfer the top of the level line to the wall and extend it around the room. The point at which the distance between the line and floor is smallest is the high spot. This is the point from which you will begin laying out the cabinets. Mark it with an X.
Mark the top of the base cabinets on the wall.
Begin at the high point on the floor and measure up 341⁄2 inches, the standard height of a base cabinet before the counter is added. Extend a level line around the room at this height.
Mark the bottom of the wall cabinets.
Draw a level line 191⁄2 inches above the top line of the base cabinets that you drew in the last step. Then mark all of the cabinets on the wall with a pencil and level to double-check your layout.