(all images in this blog post can be clicked on for hi-res versions)
One issue I had early on with Dirty Girl Gaiters was affixing the Velcro to the backs of my shoes. You learn very quickly that the sticky surface of the Velcro is not enough. I've spoken to a few other 'users' and they recommend different forms of rubber cement and superglue variants for making the Velcro a permanent fixture.
I discovered the outdoor person's version of duct tape years ago: when on expeditions I usually carry at least one tube of SeamGrip: besides its obvious function of sealing tent seams, I've used it over the years to deal with crampon holes in snow gaiters, tears in Goretex jackets and even emergency ripped tent repair. It needs to dry overnight but after that, it bonds exceptionally well even on dirty surfaces and does not become brittle over time, even if exposed to plenty of UV.
What follows is my method of using SeamGrip to do a clean job of mod-ing your shoes for a permanent Dirty Girl Solution.
The tools required are some form of sharp crafts knife to cut the Velcro and a tube of SeamGrip (which you can get at REI).
Obviously you can cut simple square chunks and slop them on with great gobs of glue. this works if the shoe has a smooth surface on the back of the heel and looks great on black.
More complex surfaces and lighter colors require a bit more finesse.
Sculp your Velcro while still on the backing taking care to keep your fingers away from the business end of the knife.
Try it for size and keep sculpting till it fits in the right spot on the back of the shoe. I try to keep them as low as possible to get more use out of the gaiters.
Make a glob of SeamGrip on a piece of paper. Remove the backing from the Velcro and use it to scoop up some SeamGrip. I find this cleaner than trying to apply the glue to the shoe or to the Velcro directly. Wet your fingers before working with SeamGrip if you don't want the stuff all over your hands.
Place the Velcro and use a piece of paper towel to dab it into place and wipe off any excess glue. Because of the curved surface, the edges will curl up. Let them. Leave for 2-3 hours and then returns and dab again. This time apply plenty of pressure for the final stick.
Leave to dry overnight. Perfect.