A few pointers that may improve the assembly process.

Paper

• Use quality craft paper and avoid thick card stock
• Most models use 3-4 color sheets per building

Printing

• Laser printer may give sharper results and last longer, but inkjet works fine
• Set printing options to grayscale

Folding

• Score the edges with a blunt object along a ruler
• I use a mechanical pencil for scoring, but retractable pens and other things work well too
• First fold should be in opposite direction of final resting position
• Fold in both directions a few times for sharp edges

Gluing

• Regular Elmer’s glue works great
• Apply glue lightly
• If attaching flat surfaces, let dry under a heavy book to prevent warping