How Do I Add Formers To A Model?

i know next to nothing about blender. all i ever used blender for is changing file types from something like .PLY to .OBJ so Pepakure and open the file so i can make a life size papercraft figure of some anime character. thats about how far my skill is for blender, also rotating a model also.

normly i have my friend in Colombia do the posing and adding formers to the model so i can build to the way i like. im to this day very happy he has helped me build all the life size Waifus i have. but as we all know corona-chan is out there doing her thing and idk how badly his country is being hit right now so i want to try and learn how to do this myself. hints why im asking how do i add formers to a model.

since idk how to add photos in a post i’ll give a link to to u what i’m working on https://imgur.com/a/UqaTBES

to the right is Rem this is the model i want to build life size. but as i said i want to add formers inside the model to help the building go along. to the left is Kongou the model was posed by my friend. as u can tell there r also red line though out the body of the model those r the formers i was talking about. i a build a model i hotglue the formers to the top of the paper to keep the shape im going for. them i use popsicle sticks on the inside of the model to reinforce it.

if u want to see what i mean here a link to part 1 of my life size Kongou build. u will see how i build these models and we i want to at the very least have formers for Rem