DIY purist crossover cabling

I have a hard time deciding on affordable hook up wire for rewiring my crossovers some day.
I am a firm believer in geometry above material, but do think material always makes a difference, Galen Gareis has over the time convinced me at least from a strict engineering perspective that geometry, distances and choice of dielectric are to be considered above all else first (generalizing a bit, sorry). But that’s physics and there surely are a plethora of unknowns to say it lightly.

So I’d like to make (at least semi-) affordable crossover cabling with some known and nature’s-law-endorsed geometry that’s actually possible for DIY construction with limited tools. (Suggestions on must-have simple tools welcome)

Do suggest affordable good quality wires and dielectrics and where to get them (in EU preferably) and of course, sensible geometries to consider. I know there’s tutorials, I just want to make sure it’s a purist approach.
Quality copper is fine, no interest in silvering my already forward sounding snappy speakers with an over-etched detail storm. (Yes, silver isn’t bright per se, but it has its signature (tied to dielectric) which just always isn’t preferable… Kondo silver or such might be great but that’s upper league.)

About 14AWG is enough for 4ohm, 89dB, 20-150W speakers, right?
I’d like as many thin conductors as possible but yes, practically applicable. Suggestions on individual wire gauge and number of conductors, please, and again, geometry considered. Don’t wanna be just twisting conductor pairs, no fun.

Silver solder, yes. How about “graphene paint”…?
Okay let’s not go there. Or maybe…

Many thanks in advance. If you think all this would be a superfluous chore, please say so. Could be that it’s more cost and time effective to just buy prebuilt wire! (Sure it is…) Though that’s not so fun either and it’s NOT DIY for sure.