I gave it a quick wipe down and I was good to go. I used two medium mirror plates and four screws that were long enough to go into the frame of the box securely, about an inch deep. These are to go on the each end of the box.
I then measured to the middle of the box sides and placed the mirror plates so I could mark where the screws would go. I put the mirror plates aside and then used a bradel to start off the holes to make it easier when screwing in the screws.
Once I made the guide holes I placed the mirror plates back and I was then ready to screw the plates on using a screwdriver.
If you have done this then congratulations you have just made a floating shelf. Now you are then ready to fix your new floating shelf to the wall. You may want a friend to help with this part. As I wanted my shelf to be centred to a picture I already had hanging I measured the centre of the picture and aligned the shelf. I check with a spirt level to see if it was straight and marked a couple of guide holes where I wanted to drill into the wall. You will need two screws and two raw plugs suitable for the screws and make sure you have the right sized masonry drill bit. It makes all the difference! However if you are attaching the shelf to a plasterboard wall make sure you have plasterboard fixings.
Once I drilled the first hole, I put in the first raw plug and attached the shelf loosely so I could check that the other guide hole was in the right place and the shelf was not at an angle. I drilled the second hole attached the other side of the shelf to the wall and I was done. A very cheap project and a great way to display your treasures. Mine currently holds a little wooden village I used to play with when I was a child.