grosbeak's technique explanation is correct. Doing this is often necessary if flying off grass. Tall or thick grass and small diameter main wheels makes it even more necessary. Each case is different as how much up elevator (pushing the tail wheel down) is required, and yes you must release all or most of the up elevator well before flying speed is reached so as to not take off into a stall situation. On paved runways little or none of this technique is needed.