First, measure the space of the wall onto which the pictures will be hung and make a piece of paper this size. Lay it on the floor.
Number each picture in your grouping.
Lay the pictures on the paper, move them around until you have found an arrangement that appeals to you.
Once you have the pictures well placed, draw around each picture with a marker.
Remove each picture and write the number of the picture on its place on the paper.
Hang the paper on the wall - just tape it up. Make sure it is straight on the wall.
Now you need to make a picture hanging tool. You need a piece of 1x2 board about 24” long. Into one end of the 1x2, in the center of the 2” side about 4” down from the top , insert a long drywall screw so that it goes through and sticks out the other side at least 1/2”. Basically what you have is a stick with a screw through the wood, the head of the screw sticking out one side about 1/2-1”, going through the board and sticking out the other side 1/2”.
Pick up one of your pictures, hook the hanging wire onto the head end of the screw. Holding the whole thing like a sign in your left hand, position the picture over it’s particular spot on the wall diagram and gently push on the very top of the 1 x 2 with your right hand. The screw will poke into the wall, indicating exactly where the hook or nail for the picture should be.
Put the nails or picture hanging hooks into the wall at each screw ‘poke’ - right through the paper. Rip the paper off enough to mark the wall with the picture number. Do this with all the pictures, take off the paper and hang your pictures. Done.
This is a picture of my picture hanging tool, from the side, the top and with a side view of a picture hanging on it, ready to mark the wall with the exact position of the picture hanging hook or nail..