When I did my templates, I did a bunch of size comparisons and scaling, then zoomed in my laptop's display until it was life-size, flipped it on its back, and traced my templates on top of the screen with thin paper so i could see the lines. The only template I freehanded was the chest armor, and that just because it was faster to freehand it to the right size.
Can you please describe your method of producing templates/using them? That will help narrow down your problem. If you can take a picture of the process, that would also be useful.