Laws of Blues Harmonica - Deep in the Mouth

Open mouth, insert harmonica... that simple.

The common error is to bring the harmonica near your mouth and pucker your lips out to meet the face of the harmonica. Your mouth closes down towards the harmonica, the jaw raises (like when blowing out a candle) and the tongue raises with it, all creating a narrow air passage that's the perfect embouchure for thin, wimpy tone.

Try opening your mouth (allowing your jaw and the middle/back of your tongue to lower with it) and bringing the harmonica into your mouth, using your lips to lightly create a large seal around the harmonica. Open mouth, light touch and all muscles relaxed... this equals good tone.