Go to a flea market, yard sale, thrift store, your attic, your grandpa's house, and find and awesome old hardcover suitcase.
Go to your local Home Depot or Lowe's and pick up some hardware! These can be found in the lumber section. It is slightly expensive- about $20 for all the hard ware and legs. You will need the metal part that screws onto the bottom, and the legs which have screws in them to screw into the metal things.
Then you will need to cut four 3x3 squares of some sort of wood, like ply wood. These are to go on the inside of the suitcase to reimburse the hardware.
Mark on the suitcase, with a pencil, where you want your legs to be. A ruler will help make sure everything is even. Then hold the hardware on there, and screw holes through the suitcase.
Then, (it helps to have two people for this one) while begin to screw the hardware in until you see the screw on the other side. Put the 3x3 piece of wood against it and continue screwing until the hardware and wood are secured.
Then screw in the legs and tada!
Note: You might have to cut the legs to your desired hight.