sub-d is the newest type of geo which tries to take the best aspects from nurbs and polygon modelling and combine them, in truth it's more polygon than nurbs.
As for techniques there are many but those are 3 types of geometry you can use for whatever technique you choose.There is no right or wrong way to model ,its up to you to practice and find a method that comfortable and right for you.
You can in theory model anything using any of the 3 types of geo but some things are easier to model using a specific type.