Selling Mistakes

Selling is not my usual forté.  Two critical sells were definitely costly for me.

1. Sold prematurely half of my position of Great Quest Metals to pocket my original stake plus $125 profit.  This stock went on to gain another 200% after costing me $950 of possible profit.
2. Sold my position of RIM at breakeven after not meeting earnings expectations.  The day after I sold out, this stock went on to recover 7% to this date costing me $500 of possible profit or more.