What would be the best Stack Exchange website to ask questions about patents? For example, the best way to patent a given idea in the artistic / creation field.
Probably in your patent lawyer's office. There is patents.stackexchange.com, but that isn't a patent law advice site.
There's the Patents Stack Exchange site.
However, it states it's:
for people interested in improving and participating in the patent system.
So I don't think that your question about the best way to patent something would necessarily be on topic.
As a general rule if you are asking for "the best X" then your question is highly likely to get closed as not constructive (at best) on any site in the network.
That would be on Patents.