For this experiment I wanted to take a photo of my wedding rings (aren't they just beautiful, my husband did good). Here is as close to my rings as I could get with my 50 mm on my camera.
No cropping to the photo, I just did a clean edit and sharpened a little.
I took the lens off, turned it around, held the camera with my right hand and lens with my left, and made sure to push the little lever that keeps the aperture closed so it would stay open. You have to have the camera on manual mode or the camera won't let you take the photo (I like to shoot in aperture priority, so that's I how I found out about that). Get as close to the object as you can and move the camera around till you find the sweet spot where you want the lens to focus on. I wanted to focus on my beautiful shiny diamond.
Again no cropping, just a clean edit and had to brighten quite a bit because I closed the aperture a touch to get the diamond more in focus, so the photo was pretty dark.
It was nice, but I wanted more oomph. So I converted to B&W, did some minor cloning of some imperfections, slight burning of the shadows to give more dimension, sharpened my diamond more, and added a slight pink layer to give a little color.