If I have it handy, I prefer gold, as I make weapons for PvM, not PvP. If I don't have much gold, I stick to iron.
I've never understood the idea of using valorite to craft weapons. The"logic" that's always related to me is that "you're more likely to hit the opponent's weakest resist", but truthfully, with the resists spread over 4 or 5 areas, you're almost guaranteed to put part of that damage toward its BEST resist as well. As anyone with even a smidgeon of Chivalry (and humans can cast it at 0 skill, thanks to JOAT, just not too successfully), can cast consecrate weapon, and most suits for PvP are as close to all-70 as the wearer can get them (often overloading in two resists to counter corpse skin), the logic for choosing any material that adds elemental damage for the purpose OF the elemental damage is pretty weak.
Now, if you're crafting Silver-etched maces (that are always Undead slayers), I can see going with Bronze, and have done so on several occasions.
But, most weapons have little need for "Lower requirements", and one can always PoF a really good weapon for durability (or letting the buyer do it), instead of making it of a metal where you'll lose more than the value of a vial of PoF smelting all your rejects at the end of the runic hammer.
Typically, the only weapons I make that aren't gold or iron is the previously-mentioned Silver-etched mace.
ENHANCING looted items, on the other hand, is a whole other matter. You're more likely to loot something with higher requirements, than ever make one with a runic, and since you know what properties the weapon already has, then it makes sense to enhance to maximize damage if you don't have Consecrate up.