Just to add a little to what CC said....If you need to drop two anchors you're probably in some strong currents.
As such, you need to have at least a 2:1, preferably a 3:1, ratio of anchor line out to the depth that your're anchoring in. So set your best anchor with the most line first. Move the boat directly away (180?) from where you set your first anchor until 4X-6X anchor line is out and drop your 2nd anchor. Pull in 2-3X of your first anchor line while allowing the 2nd anchor line to free-float and cinch your first anchor. Then tighten up your second anchor line and you should be good. Reverse the process for pulling anchor.
If I'm by myself when I need to do this, I set my first anchor up current and drift back until I'm in position to set my 2nd anchor. Then you can just use your anchor lines to pull your boat back for positioning.
Think through the process before you actually attempt it.