Pepakura is a great achievement for anyone and requires a massive amount of hours and skill to get right. Over the years i have spent hours making helmets only to accidentally squash it or warp it during the resin stage. Here is a great tip that will save you hours, if not days of pepping time.
Step 1: Using Foam Templates
Whenever your searching for pepakura files, instead of using the normal files, search for foam files instead. (Or modify normal files to foam). But instead of using foam, use cardboard. Draw around the printouts onto corrugated card sheets, cut and glue with a glue gun. Assemble as you would foam using the pep viewer as a guide. After its complete you can fibleglass and bodyfiller as you do normally.
Step 2: Conclusion
Using this technique you can save hours of time and money (foams expensive, cardboard is free) This is ideal for people who dont like the finish that foam has and still prefer the fibreglass option, but hate flimsy fiddly pep pieces. The ironman helmet shown took 2.5 hours to complete and is solid with minimum warping when fibreglassing. I also made a clonetrooper chest and back in around 5 hours.