In effect every guitar picking techniques should develop themselves,  but generally people are too lazy for that so there are some standard techniques available. The big problem with learning these techniques is that unless someone who already knows them correctly is teaching you, you will most certainly learn them defectively.

How does that happen ? let’s suppose you are trying to learn the picado technique, the best thing to do is perhaps take a few videos of Paco De Lucia and study the movement closely, then practice it on the guitar. Problem is that you will most likely miss a few important details, and you won’t be able to move your hand quite like him. So this leads to a faulty technique, which in turn leads to mistakes while playing, which is the kind of thing we should want to avoid.

So how should you learn guitar picking techniques ? Get the general idea, picado – index and middle fingers alternatively, cool – and record it. Record yourself doing the technique, then compare the video with the way Paco De Lucia is doing it. This way it is easy to see the differences and you will easily understand where you are wrong and what you should try to do. This is the technical approach to learning techniques, comparing positions and movements.

Another way is to try and make the guitar sound the same as the song, but this is very unreliable as in the case of picado it is highly unlikely that you will be able to move as fast as Paco De Lucia even if you’re using 4 fingers for a tremolo instead of 2. Still I recommend trying this as well as the other method.

Using both methods should lead to you developing your own style and guitar picking techniques, and that is the point of playing guitar.