Is it a sign of weakness ?

[thir]

Is it a sign of weakness to ask another Dom/sub for advice on how to be a good Dom/sub? or is it just not done?

No, it is called shared experience. Or I see it.

Subs do it a lot more, though, perhaps from this idea that a Dom must be born perfect. An idea that both some subs and some Doms seem to have. A great shame, as it can get in the way of growth.