Ditto this!what i normally do is when adding the hair for individual braids when you start at the base braid the hair in place a few times if that makes sense without pulling down.
If you are pulling down while braiding it will cause it the braid to be loose at the base or "slip".
What this will do is provide a firm hold with the weave and your hair combined. While braiding it in place, you can do a lil test pull to see if it will slip, if it doesn't, then you're good to go on and start braiding downward if you so desire.That does make sense. I will try that. Does that method make the hair bunch up near the base?
The last link is a very good example of how it's done. It's a lil loose in the demonstration, but only you will know as to how loose you wish your braid to be. So not to be too tight on your roots or pulling on your hairline.This site had helped me to braid with extensions
http://www.growafrohairlong.com/braidreg.html
This link will help you to for the root of the braid:
http://www.doctoredlocks.com/store/demonstrations/collections/braiding.html
This is also another option indeed!I usually do a tiny cornrow in the direction that I want the braid to hang. They never slip that way.