Usually the counters that made it into my watchlist have been assessed for their fundamentals more or less.
For these counters I set several target prices to enter based on support / resistance levels over several time frames.
When the price alert is triggered, I will not press the buy button straightaway. Because target price set is not a hard and rigid figure. Rather, I treat it as a fluid figure which I will sit up and place closer attention to when hit.
So when that happens, I will check for any latest news for that particular counter and whether it is good enough for me to buy straightaway or whether it has more room for the price to fall.
By doing this way, I have saved quite a fair bit on my entry prices over the years.
So say I decided to hit the buy button, I will usually buy in 2 to 4 batches. No hard and fast rule here. I do that because I can never catch the bottom so by buying in batches I made sure I stay vested in the market for the counters that I want to own.
Time in the market is much better than timing the market for me.
Most recent example of such trade for me is PayPal which I bought a small batch last week.
$PayPal (PYPL.US)$
NANA123 : Time in the market is much better than timing the market