IrfanView is a free program used to manipulate and create artwork. You can download the most current version here:http://www.irfanview.com/
This is how I create and import artwork for my modules very quickly.
The first step is to get some artwork. Usually, I just jump on either Google Images or Bing Images and search for a term that will get me the results I want. In this case, I searched for "D&D Wizard."
Once I find an appropriate image, I just save it to the hard drive. Usually, you can just right-click to get a menu of options that allows this.
When it's on the hard drive, I just open it up in IrfanView (which I have set as my default viewer anyway, since I hate the default Photo viewer that comes built into Windows 10).
Since I know the standard pic in FRUA is 88x88, I know that I am dealing with a square ratio. I try to grab an area that is roughly square with the selection tool. It's okay if it isn't exactly square, but getting it close will help me know what the picture will look like in FRUA.
Once I've selected the area, I use the Crop Image tool to cut out everything I don't need.
Now, we need to resize the image down to a size that is close to what FRUA needs. Since I use UA256, I try to get the image around 100x100 to give me a little bit of room to work with. Also, I always make sure that the numbers are both even (it's a quirk of UA256 that if either of the numbers are odd, the image won't render right). In this case, I just set it to 100x100 with the Resize tool.
Once the image is resized, I use the option to decrease the color depth in the image to 256.
As the final step, I save the image as a PCX file (something IrfanView can do natively) with an 8 character name that DOSBox can read. I then use UA256 within DOSBox to grab the image and convert the color palette, and then import it into FRUA. You can see the final results below.