For the first 20 years, I never added a floating selvedge. I don't remember what finally got me to give it a try. Once I did, though, I have never looked back---although I have tried several different variations on the theme. Currently, this is what I do, but this is not to say that my method is set in stone.
I won't go into all the different variations, but now I wind an end that is the same yarn as the warp and double it. The color I select is the color I will use for my weft (if I know what color that will be). If I don't know what color I am going to use for the weft, then I match to the warp (especially if the warp is a different color on each edge). I wrap the double end around any handy cone of yarn (leaving a couple yards), and place the cone on the floor in the appropriate place. I take the loose end, bring it through the loom next to the last (or first) warp end (but not putting it through a heddle. You can see in the picture below, I skip one dent (I have skipped 2 dents in the past, but currently I am playing around with a single skipped dent), and tie the end onto the bar with the other warp ends.
Once the floating selvedge is secured in the front, I clip weights (which are easy to adjust as I weave) to selvedge thread in the back. The red weight is 6 oz. The orange one weighs less, so I added the ever popular film can with pennies to equal 6 oz.
Presto, you are ready to go!
Jury duty is over.
You can see that I am already weaving. Pictures will arrive later.