A few questions on DIY nightmares

I'm about halfway through my helmet scratchbuild with cardboard and wanted some advice from the veterans of TDH on what's just a bad idea to DIY. After hearing a few horror stories about ill-fitting flightsuits on the forums I'm leaning toward purchasing one from bobamaker or similar. I'm a fairly competant and comitted builder and intend to make as much as I can myself but to save me some headaches, does anyone have a few words of wisdom? What other pieces are best purchased? I'm also concerded about the codpiece and may purchase that because of the difficult contours and the obvious need for comfort in that area. Any advice is much appreciated!

I would buy the helmet. A good looking helmet makes a so-so looking suit look better. I've made my own jango cod piece in the past from the WOF templates. It worked just fine till I upgraded to a fiberglass version. Flightsuits are actually not too bad to dIY. If you can find some coveralls that are close in color, or dye them, the sewing part shouldn't be too bad. Just need to add the extra short sleeve and remove some pockets.

Unless I have a horrible bondo mishap when it comes time to shape the dome I think my helmet will turn out well. I've been following antman's tutorial and was pleased to find how rigid the construction was. I may re-enforce the inside with resin at some point if it becomes necessary. As far as the jumpsuit goes, my fears have somewhat subsided after finding WOF's soft parts templates so I think I'll dive into that soon. Thanks for the advice!