Well, no, first you discuss the idea in a Working Group mailing list, which is like HN – you get lots of great negative feedback. When you have fixed all your initial bugs, you write a draft RFC. With which implementers can create independent implementations. If there are not anyone willing to do this, this is a sign that the idea is not wanted enough, i.e. not widely useful enough to warrant an RFC in the first place. The implementers will find bugs. You fix those, and discuss some more. Eventually, you, the mailing list and the implementers will be happy with the standard, at which point you move to have the RFC published as an official RFC.

Anyhow, this is all for a “Standard track” RFC. An “Informational” or “Experimental” RFC has no such requirement, and can basically be submitted by anyone for anything.