How to assemble a Halo Reach Foam thigh?


Hey guys, so lately I have been working on costumes for my films and I finished tracing everyone templates. Before I continue with the construction of the costumes, I just would like to ask how people assemble their armour when it looks like it over laps on certain areas like the inner part on the Halo Reach thigh peace. Do you guys take several mm of the peace then glue on the inside or do u through a peace of scrap on the inside and glue the 3 parts together? I would love to hear what everyone's methods are.