Linda Bradford Raschke mentioned some wisdoms of short term trading in The New Market Wizards: Conversations with America’s Top Traders.

I put a great deal of effort into getting the best entry price possible. I feel this is probably one of my strongest skills. In day trading, a good entry price is critical because it buys you time to see how the market will react. If you buy because you think the market should bounce, but it only goes sideways, you’d better get out. Part of the trading process is a matter of testing the water. If your entry timing is good enough, you won’t lose much even when you’re wrong.