It is easy to make a large number of these slides in a short period of time. That can be handy when making them for a whole troop. I try to make a special slide for everyone that attends summer camp. They are individualized to memorialize something outstanding or funny that happened to the person at camp.
With the popularity of the personal computer and the Internet, clip art has become much more readily available. To make a nice looking slide (if you are not artistically inclined) simply locate an appropriate piece of clip art and print it out. You may add text or dress it up if you wish. You can make the project neater by putting the clip art inside a shape that is the outline of the background you want to use. That is, paste the clipart inside a square, circle, or oval. The outline of the shape will provide guidelines for cutting it to the correct size and shape.
After you have a hard copy of the image, cut it out. Cut a piece of craft foam to the same size. Put a small amount of white glue on the foam and spread it thin with your finger (make sure to get the edges). Wait for the glue to start drying, then put the clip art in place. I have had problems when putting a colored image on when the glue it is too wet. The ink has a tendency to run. Press the clip art firmly in place.
Another approach that I started using just recently is to cut out the image and get it laminated. Laminating is the process of placing the image between two pieces of clear plastic. This is heated to a temperature that melts the edges together. It requires special equipment. However, for a small fee lamination services are widely available from school supply stores, schools, and many other places. This makes for a waterproof and very durable slide. Some laminating plastic is pretty thin and the slide tends to curl. If thicker laminating material isn't available, laminating them twice will help. Then just glue a PVC ring to the back using Hot Glue.