Your best ideas will probably sound a little weird out loud the first time. Say them anyway.

New ideas have no established language yet, so the first attempt at saying one comes out awkward and gets heard as muddled rather than original. That awkwardness belongs to the newness, not to the idea. Waiting until you can say it perfectly usually means never saying it.

Bring the half-formed one to the group this week and admit it is rough before you start. Give it two sentences rather than a speech, then let other people push it into shape. The ideas that end up mattering are almost always the ones somebody was willing to say badly first.