If you've only just started doing it, don't fret. You'll get the hang of it in time.
I don't know if my explanation in the link below helps at all, but I don't wrap the additional hair around my own. Instead, I use my thumb and the pointing finger of the right hand to hold the point of cross-over point of the extension hair at the base of my hair. In other words, I use the fingers of my left hand my hair so that when I hold the extension hair against my own, I have it gripped at the lowest point possible. And then while not losing that grip at the base, I use my fingers to split my own hair into 3 sections to match the extension hair. So while gripping with right-hand fingers, I use left fingers to pull out the left side of the braid section. Then the left fingers take over the base hold and I use the right fingers to separate out the right side of the braid section. That leaves the center part which seems to be the main part the grip is on and once again right-hand finger and thumb take over the base hold.
Now w/o losing that the pointing finger of the left hand reaches over the middle section of the braid to grab the right hand section and bring it over the middle so that it now becomes middle. Left fingers now take over the base hold so right fingers can reach over to the left section of the braid to bring it over the new "middle" so it becomes the middle now. Again there's a shift in base until you no longer need to grip the base.
Link to a thread where I shared some pics that I hope shed some more light on this.