regular electronics wire in Europe is 0.14mm^2. The equivalent of AWG #24. I prefer to use 0.25mm^2 (AWG #22). It's a bit thicker, and while it may not have an audible improvement, it's harder to break loose from half-assed solder joints as well or have internal breaks.
Meanwhile @ TGP: "I was especially put off by the religious banterings written inside the LDO pedal. I guess he felt it was necessary to thank God that someone payed $389 for his tubescreamer!"