From what I've heard, practiced and according to Sunnah, one must recite the isti'aadah, spit (not literally saliva) three times to the left and ask Allah to interpret the dream according to His wisdom. If it is in the middle of the night, it is recommended that you do not sleep on the same side you had the frightening dream. As for recounting the dream, preferably, to be on the safe side, I wouldn't recite the dream straight away, but, if you wanted to, because frightening or 'bad' dreams are from Shaytaan, before you do, the isti'aadah must be recited so the interpretation follows the refuge you seek with Allah, from Shaytaan, as opposed to the contrary.