Materials:
Glass vase of choice (jalex's comment: Dollar store has great ones)
Picture to decoupage (I used a photo copy of a fabric print)
Clear drying craft glue or decoupage medium
Cream colour paint [I used an "enamel" acrylic paint]
Taupe colour paint
Scissors
Tray of water
Paper towel
Window cleaner, such as Windex
Craft Knife
Cutting Matt
Sea sponge
Instructions:
Choose a photo, gift wrap, etc to use as your decoupage print. Using a craft knife (scissors can be very difficult for small prints), cut your picture cleanly.
Drop your picture into a tray of water. It will at first curl up and then flatten. As soon as it flattens, remove from water and pat dry with a paper towel. This technique will relax the paper and prevent it from wrinkling when you apply it to your glass.
Apply glue to the full surface of the front of the image and place on the inside of the vase (the picture will show through the glass). Apply as many images as you like and they may overlap each other. Once your image is in place, apply an even coat of glue over the back of the image and allow to dry completely.
Now that all the glue is dry, with a small amount of window cleaner, remove any glue that is sitting on the glass. The glue will remove easily with a paper towel dipped in glass cleaner.
Allow to dry completely. Before applying my cream colour paint, I sponged taupe coloured paint on the inside of the vase. Use a sea sponge for best results and dab gently over the entire inside of the vase. Allow this paint to dry completely before moving to the next step. Paint the entire interior area of the vase with cream coloured paint. Allow to dry at least 24 hours. Repeat painting until you can no longer see through the paint. Depending on the paint you use, this could take any where from 3 to 5 coats of paint.
Heat set the paint, if required by manufacturer instructions. Because this vase is painted on the inside, you can not fill it with water, but you can fill a glass with water and insert inside the vase for fresh floral arrangements.