Guilty as charged.
IMHO, the important parts of the image are the people (or car, building, pet, whatever the portrait holds). The rest is noise. The 1st thing I do with a portrait is use GIMP to remove the background noise. Then if there are more than one person in the picture, I try to balance the lighting on the faces. GIMP lets you circle a section of the picture to change the contrast, brightness, etc. That helps with the GIMP/Inkscape Trace Bitmap process. Then I look at the layout and try to position the people together so the image looks like a staged studio portrait. That can be tricky if their depth of field was different, where you might need to scale the sizes (didn't do that with this picture, just dragged the girl closer to the guy). In GIMP, you can use the rectangle, circle, or lasso to surround a part of the picture, then Ctrl-X (delete) Ctrl-V (paste) to make that section movable.
Once they are in good position, crop the image to center the subject, then save as a jpg. Go through the Filters (cartoon, photocopy, edging, etc.) then save as another jpg. You can then go back to the unfiltered jpg if needed. Open the filtered jpg in Inkscape (while still open in GIMP) and select "link". "Link" lets you go back to GIMP to make edits that will show up in Inkscape. Wiggle the Trace Bitmap parameters until you get a good trace then save as a .svg. NOTE: if it is a man and a woman, make sure the woman looks great. The guy won't much care, but the woman needs to look good. Remove wrinkles, double chins, stray hair, wardrobe malfunctions, etc. just like a photographer would.
Load the .svg into GIMP - it will have the checkerboard (empty) background. At that point I usually set the size to something that would fit into a std frame (4x6, 5x7, 8x10, 8.5x11). The image usually is not that proportion, so make the image smaller than the frame size then Image/Canvas Size (center, don't hold proportion) to keep the image size but grow the canvas to the frame size.
Use the fill bucket to find and fix the islands, build bridges, correct for bad peninsulas, then sign and save it.
Anyway, that's my process. Some picture might need to have some background kept (a waterfall or the Eiffel Tower would be important parts of the picture), but most pictures can be reduced to just the main subject (like this picture, or the Model A Ford, the Steam Bus, Stone Church, etc.)
