It's taken me a while to really get comfortable with my macro extension tubes. Another reason I took on this project was because I wanted to become more fluent with my equipment and a stronger photographer. I had purchased a few of these extension tubes not too long ago and had been using them in shoots from time to time, especially in my newborn sessions.
The trick of these lenses, I've discovered, is to not use the most magnified lens. The focal length is too small to be able to compose the image well enough. So I use one of the weaker lenses, that way I have a little composition room to play with. Since I figured this out I've been snapping these on during every baby session I can.
I've been a little apprehensive to use the macro lens with moving subjects like my never-stopping Tman. But his lashes, they are like the 8th wonder of the world. So you give him a little peanut butter playdough, and he'll be occupied for a few minutes, looking down, just enough time to capture one--just one--photo of these beautiful eyes.