Have to laugh at this thread! I did buy a binding tool but never could figure out how to use it despite written directions and youtube tutorials! I did read the Fons & Porter method and have gotten so I can do that without all the markings and don't end up with that "bump" you get when it's too loose.
First, unless I'm dealing with curves I don't use bias binding, but do double it--usually 2.5" wide unfinished, folded over as I like to leave a little bat so the binding doesn't feel thin.
When I've got about a 12-15" gap between the ends of binding (I plan for a 8-12" tail on both ends), I lay the unsewn tails on the quilt leaving a 1/4" space between the two tails, folding back the extra tail and fingerpressing it.
I then open the two tails and with RIGHT sides together I sew the 2 tails together at a diagonal just as you would putting to strips together with a bias seam. I don't cut the extra tails off until I check that it will lay flat. Once I know it will work, I trim off the tails and then sew the remaining binding down. The key is the 1/4" space.
(oh--I have found my binding tool makes a dandy French braid template!)