hi, i use 3mm roo lacing and the width of the bracelet was about 12mm. i used the same width lacing for the whole project. To start the lacing, come up through the hole from the back, go over three wrappings and back up under two, then down over three, crossing over the first down abit so when you go up two the next time you end up on the other side of the first down. now doesnt that sound like the worst instructions you've ever heard!
here is a drawing... the black lines are the wrapping lace, the red lines are going down over the wrapping, the green lines are going up under the wrapping lace.
hope this helps
good luck