One of the biggest things to check before going to the resin stage is to make sure the armour is symmetrical and shaped correctly. This is the fiddly stage. I found that lots of extra gluing of tiny paper tabs over areas that were weak helped tremendously.
1. Placing the armour over a mannequin. I borrowed a very small female torso, so I put a t-shirt on it then stuffed it with newspaper to bulk it out.
2. When the armour is spread to shape, I found the spine tended to collapse slightly so I wedged a strut in there temporarily to keep it spread the right distance.
3. A strut inside at identical points both sides helps shape the torso.
4. Once the armour is hung correctly, it's time to space the pieces. As vshore100 advised me, the chest and back don't actually meet up at the front, they just kind of float apart. More support will be underneath to connect them later. Until then, it's sticky tape to hang it in place.
5. In places where the paper or joining tab was too flimsy to support itself, I glued tiny card tabs to reinforce the joins.
6. Some final re-pinching of folds to correct and adjust shape and form before the resin stage. Once resined, there will be no turning back.