Expedient hinges for kits; what is working for me:

[Wickersham Humble]

In the class of car kits I build -- mostly all old annual kits back to 1960 that I squirreled away back then -- I have struggled to make hood/trunk and rarely door hinges like I've seen exampled in the model press.  Mostly I do the 'bent aluminum jewelry wire' hinges, which are not too hard to retrofit to very old promo-style bodies (especially ones from ancient 'curbside' bodies where the hood has to be cut open, engine compartment details created, etc.) and mostly have an acceptable look on the show tables.  However, engineering such using wire and styrene tubing has it's inherent limitations, the biggest being that the don't appear at all like the stock 1/1 hinge.

I like having the hood/trunk lid appear natural and attractive in both open and closed mode, which isn't always a slam-dunk with the wire/tube fabbed hinge setup; mostly they look okay when open, but don't settle down into the lip of the cut-out opening I have to create.  Eg., without the hinge, the part can be made to nestle down into the cavity with some conviction and give a good, smooth appearance, like the 1/1 car.  But after mounting on the wire hinge, where it looks okay open (showing off what I create for engine, etc., or trunk junk) it no longer seems entirely congruent with the opening from whence it sprang -- so to speak.  This is exacerbated by the fact that hood/trunk has to nest happily on two different planes, horizontal and vertical.  A problem!

What I came up with (finally getting to the tip) is to replace the jewelry wire (or copper, whatever you use) with the lighter gauge of solder wire, and it sure works better!  Aluminum is pretty malleable, and bends well enough, but the hinge pieces I have been 'engineering' often as not fight the open-shut fit, and don't give a great appearance.  Even after a lot of trial & error fitting, using wire-bender pliers and the rest, getting the part to fold down into the opening acceptably takes more time/effort that I may be worth in the end.  Because every kit has it's own shapes and limitations for space, no one design of hinge fits all, certainly.  But using light solder wire, usually one can get a better shut-fit because the metal can be 'finessed' to a better conformation than aluminum/copper/etc. and there isn't appreciable down-side, either.  Trying to massage the stiff-wire hinge often as not results in one of the styrene tube mountings breaking loose from the kit body, or paint damage in my experience.  This simple change can prevent that.

Amongst the hundreds of tips & techniques, someone may (must!) have hit upon this trick, and suggested it, I suppose; I didn't see it.

Now, if your elite build requires truly accurate scale hinges, this isn't for you. Frankly, I've seen very few hood/trunk hinges that both work well open/shut and look scale realistic, but...  You undoubtedly have the very light guage solder wire on your workbench; give it a try.  Wick  [sorry, not pics]