This stance, as its name suggests, is very strong in the forward direction for both attacking and defending techniques.
The feet are about as wide apart as your own shoulders, and a long step forward in length. The front foot should be basically straight, with just a slight inward turn. The rear foot should be as straight forward as the flexibility of the ankle allows, but certainly not exceeding a 45 degree angle.
the front knee should be pressed forward until it is over the front toe, but just slightly to the inside of the front toe if observed from above. The rear leg should be very slightly bent. The hips will be either at a 45 degree angle (hanmi), or will be straight forward (irimi). The weight should be distributed with 70 percent on the front leg and 30 percent on the rear leg.
The back is straight, the abs are tensed slightly, and the hips are pressed forward and rotated upwards.
The shoulders will either be squared forward or at a 45 degree angle, depending upon the technique being done. The head is held level and vertical.