Things you will need:
Old card board box or poster board
Colored construction paper
First find the picture you want to frame and cute a piece of card board out in the center of it that is about a ¼ inch smaller then the picture make sure the card board is about ½ inch bigger then the picture itself.
Cute a piece of construction paper that is a little bigger then the construction paper and make sure it overlaps the cardboard so that you can glue the paper to the back of it so that no seams are shown.
Fold the paper over the board and glue it in the center first on the back of the board and then around the edges of the back of the board. You can also just color the cardboard with a marker the color you want it which is much easier.
Find decorations such as heart cut outs or stars or even write words on it and decorate the frame however you would like it.
The final step it to cut out a piece of paper that is the exact same size as the piece of cardboard so that you can make the back. After you have the piece of paper cut out glue the two sides and the bottom part of the paper leave the top open so that you can insert the picture. Make sure you let the glue dry before you insert the picture into the frame.
Have fun with it decorate as many as you would like at one time they are not very time consuming at all.