I'm brand spanking new to trading today and pulled three trades only to cancel all three all because i still don't know what I'm doing.  

When real money is on the line the emotional component is much different.

I settled on GSAT and made a note of entry, exit, loss threshold and position size 

1st attempt was pre-market.  I couldn't even buy, so I cancelled once I saw the price jumping up.  2nd attempt was right after market open but my bid was way below the ask.  So I cancelled again.  The ask was above my original entry, but I figured it would still work out. I set the order again a little higher and then realized that I was chasing after this thing like a degenerate gambler.  So I cancelled for a third time.  

So the big takeaway for me is learning how to use the software (Etrade) and timing the entry point.  Also, don't chase.  Trade like a sniper, like Tim says.