Macro is a challenging subject to photograph. Light, especially, can be a real struggle, so you often need to add extra light to overcome the bellows extension factor inherent in all true macro lenses. But dedicated macro flashes and ring flashes can be very expensive (at least if you want a good one). Are there other options?
Well, you can butcher a Pringles tube. We posted a tutorial on this way back in 2011 to be able to make use fo the popup flash for macro, but this video from photographer Micael Widell shows a similar method using an on-camera flash, allowing you to get much more power for those extreme close-ups.