I have made a couple of little diffusers that I use with the pop up flash for my S5 IS, that I am getting pretty good results with, that can be made for almost nothing.
While I used welding wire, of a nice thin but springy hardness, you could start with just a common coat hanger. Bend this around something a bit smaller than the barrel of your lens, or extension tube. It will probably have a little spring-back, but, a little squeezing and tweaking will bet a spring fit to the lens.
To begin with, the wire will have about 6" on each side sticking straight out on each side in line with the top of the lens. Then I bent it forward and out at about 45ยบ to the line of site from the front of the lens.
I sprayed the extended part with contact cement, and lay it on a piece of white plastic grocery bag, and fold the outer part around the wire. This glue sticks to the bag instantly within seconds of being sprayed.
I then trim the wire and excess bag, so that I have a nice soft ~ 4" x 5" white translucent diffuser in front of and above the lens, that is easy to adjust the levels through the camera, and stores in the bag without even taking any space. I put it in the camera space, then lay a large lens cloth over it, the put the camera right in on top of it.
I usually shoot in AV mode, at F8, which is my smallest setting, although I wish for smaller, for better DOF.
After using this set-up for a couple of months, I found that sometimes the bottom portion of the shot would be under exposed. So I bent another wire, and glued a foil faced piece of plastic made for putting in the car window to keep the sun out. This bounces enough light back up to fill in the bottom for perfect exposures.
If your subject will sit long enough for more than one shot, the flash level gets adjusted by pressing the function button, then down to flash, the >>for +, or <<< for minus.
Maybe someday soon I will start sharing my shots here. I am a woodworking artist by profession, but being out in nature is my passion, and I am just weird enough to bring a different eye and aesthetic from what most people see.