Visit a local supply store and purchase a laser level if you do not already have one. Using a laser level will not only make the task much easier but will also help you save a lot of time.
Depending on the height of the wall on which you are going to hang the artwork, decide the height of the painting above the floor level. For walls of average height, ideal distance between the painting’s bottom and the floor would be 66 inches.
Set the laser level at the height which you decided in the earlier step. If for some reason, you are using the conventional method, use a tape measure to mark the pre-decided distance along the wall.
Determine the position of each painting on the wall. For paintings of same dimensions, simply decide the order in which you would want to hang them in a straight line. For a group of paintings with different dimensions, draw boundaries of each of the paintings on a large piece of butcher paper. Refer to this drawing for hanging the paintings. To get a practical feel, temporarily attach the paintings according to the decided pattern. Use gum fixative for this purpose. Make any changes to the position of the paintings if required.
You will need to start with the painting which you plan to be hung in the centre of the wall. Use a tape measure to accurately determine the distance from the hanger at the back of the frame to the frame’s top edge.
Moving down along the wall from the laser line or line mark, mark a spot. The distance between the spot mark and laser line or line mark should be the same as the distance that you measured in the earlier step.
Properly install the picture hook into the wall. You would want the top of the painting to be fully level with the line that you initially marked on the wall. You can accomplish this by installing the picture hook in such a way that the bottom of the hook’s cradle directly over the line marked in pencil.
Finally, follow Steps 4, 5 and 6 to hang rest of the paintings.