Mark the center on 12"x5.5" boards using a tape measure. To make the two smaller vases, you will then divide the board into 4 equal squares of 3" each. For the taller vase, you will mark (2) 3" squares and (2) 6" rectangles.
Make each cut, beginning with the shorter cuts. Remove tape after all cuts have been made.
Find the center of each 3" board using a tape measure and make a small X. Use a small drill bit, make a pilot hole in each. Switch to a 1/2" drill bit (or a 1" depending on the size of your vase) and drill through your pilot hole on each.
Center your vase upside down over each hole and trace around the lip of the vase. Carve out a small lip for your vase to sit in. It does not need to be very deep, just enough to give the glue more surface area to grab.
Apply Super Glue or Gorilla Glue to both the wood and the top rim of the vase. Set aside to dry.
While the vase is drying, assemble the remaining pieces. Once all pieces have dried, attach the top/vase piece to the rest of the vase using wood glue. Let dry for 30min to an hour. Use a high grit sandpaper to soften any rough edges and add flowers!