That has been the toughest part for me too, but I guess it is good to learn while you still don't have much. I started watching the market prices when it the SBD/STEEM ratio was between 0.6 and 0.7. I didn't have a frame of reference at the time, so I had no idea how good that was. I wish I had converted all of my SBDs to Steem Power at that point, but again...I am just trying to learn as much as I can at this point.