Not trying to rail road your poll but I'd say none of those. The thing that's increased my fluency the most is to not try to fix it. General anxiety reduction helps the most. The less attention I give my stutter and the less importance I let it have on my life the more fluent I am. If I feel like it's worse then usual I won't try to fix the stutter I'll work on reducing anxiety by meditating for ten minutes a day and making sure I'm getting plenty of sleep etc