where should i place my tongue? close to the teeth or pull back? thx!

I asked the same thing. With an individual it can very a bit; everyone is differet. But my professor said that in the long run you will gain greater speed by putting the tongue just behind the teeth. Make sure when you double tongue you keep the air going on the back stroke.

I always put my tongue on the roof of my mouth, But whatever you do do not keep your tongue there for the whole song! Make a ta sound. See `ya!