Been there and done that and still sometimes it happens. A few questions I ask myself whenever contemplating a trade
1. What influences the stock purchases? FA, TA or random tip off a thread?
2. What is my timeframe for holding?
3. What will define my entry point? Eg I've read in a few places to become an expert at only one thing such as buying a test of support after an initial spike or breakout.
4. Can I make sense of the chart and anticipate the next move?
5. Can I make sure that I don't get attached to a stock for whatever reason?
I don't make any assumptions as to your level of experience but the most successful and experienced people I've seen on these threads always work to some set of rules. GL