The main thing with inserting forms is trying to get the angle correct so that the pop-up will work the way you intended. This example by a student, show a mysterious form at the top of the page. The form stands upright when the page is fully opened. The theme for this book was "Fear".

Begin by folding a paper in half. This will be the background page. Fold another piece of paper in half and cut out a symmetrical shape.

Open the symmetrical shape and make about a 1/2-inch cut on the fold at the bottom of the shape. Fold the form closed again. Fold the bottom of the form back on each side to create tabs.

Take the shape and put it on the folded background paper. Decide where you want the shape. The example shows the shape at the top of the page. Line up the shape so that it touches the folded edge of the background paper and it stays within the boundaries of the background paper. Take a pencil and trace the folded edge on the shape (where the tabs are). Take scissors and cut this line.

Take the shape and put it inside the folded background paper. Put the tabs into the slit so that the tabs are now on the back. Glue each tab onto the back of the background paper so that they are hidden.

I sometimes glue another piece of paper over the tabs to make the insert stronger. Let the page dry and then decorate it.