Here's a video that was shown to me by a fan who knew I initially had some flow issues with my holy grail pen, my Pelikan M800 1.5mm italic. This is nibmeister John Mottishaw tuning my pen (not really my pen, but an identical one) with what seems like the greatest of ease. It's a testament to his skill and experience for sure! Kinda makes me want to get into nib tuning ;)
I have heard John has a great reputation, though I have never met him or had any work done by him (so don't consider this to be an 'official' endorsement here, no affiliation)....have any of you ever had anything tuned by him? How about other nibmeisters?
Link to YouTube for more viewing options.