I use poster board to create templates. It works really well because it is quick and easy to cut and fold. But it also has some strength so you can fold it into three dimensional shapes just like you would with cardboard.

But there is a benefit not readily apparent. When you use poster board templates you can experiment quickly and easily with shapes and sizes. And once you got the right shape/size you can then use the template to create the final cardboard piece.

Here is an example.

I made some measurements and made my best guess for the size tower roof I wanted. This is actually the third one. This one is just the size I was looking for.

Here it is folded up into the tower roof shape.

It looks good.

We transfer that pattern over to cardboard.

And there you go. The tower roof exactly as I wanted it. And, I saved a lot of time and effort by first working with posterboard.

Keep this in mind when you are working with cardboard. It's a handy way to work more efficiently.

Another kind of template you can make is for repeating patterns. On my World's Greatest Cardboard Castle I have a lot of repetitive shapes. To keep them all very neat and very uniform I use a template that I drew and cut out of posterboard.

Using templates also can save you a lot of time.

I created a template out of cardstock for durability. And use this as a pattern to draw out the shingles on the cardboard paper. Using a template insures I can do this process repeatedly and all the shingles will be consistent in size and shape.

Next I can cut out that strip of shingles. Nice! I have to make lots of these strips!

Glue them in strips to the roofs of the castle buildings. They look great!