2 differnt ways to work out your

[filmsimon]

Hi,
I've been watching a video from Full tilt poker about odds and outs. They've advised that you can use a system called 2 and 4. On the flop you times your outs by 4 to give you your percentage chance of hitting what ever card your going for to make the best hand, then on the turn you times your outs by 2 to give you the same thing.

My problem is that i've also been given another method. when your on the flop you times your outs by 2 and add 1. You also use this method on the turn.

Looking at my chart of percentages Vs out it's seems that the latter method works the most acurate but is there something I am missing in the first method?
Is the 2nd method giving me my percentage chance over the turn and river? If so would this be a better method to use or should i work out my percentages at each individual stage?

I know it depends on how much is in the pot as to whther you call or not but I was wondering which method other people use and if anyone uses any of these.

Thanks

Simon