Stop the long meandering discussion by actually doing something. Then the discussion refocusses to action. Do this fearlessly. It's easier to ask forgiveness than permission. Consensus only works on a macro basis. Minor details promptly suffer from BikeShedding.
JustDoIt doesn't seem to me to always be the appropriate model for group projects. Yes, it gets things started and going. But when people are actively discussing an issue of larger interest, it makes sense to me that the issue be discussed, various ways of doing something examined, tradeoffs weighed, and then execute a change based upon some consensus. Am I missing something?
When more than one person cares about a topic, JustDoIt results in one person's vision being realized, and a cycle of potentially conflicting changes necessary to stablize the code.
JustDoIt is for micro issues. Macro issues require discussion. We can agree the sky appears blue but not exactly what shade of blue. It doesn't matter what color we paint the BikeShed in the end. Besides the converse is that a lot of opininons on what should be done are expressed by those who never do anything and this results in a hegemony where the little bees work while the queens micromanage them. Discuss big issue. For the little things...JustDoIt.
see also: LazyConsenus