Range cannot be improved through practicing basics. With step-sparring, the distance between opponents is kept large for safety reasons. In floor and pattern training, techniques are usually locked out and held on the target. Therefore, range must be practiced while free-sparring at the true range for actual combat.
Use the correct stance and position for long/close range and snapping/thrusting techniques. Vary distance by moving within a stance or changing stances. Use the hips, stance, and body rotation to increase reach and find the exact distance needed to extend a technique fully.
Develop sensitivity to gauge people's reach, and then adjust the range to allow them to miss just barely. This will help you not to flinch because things are flying at your face, and it will give you the posture and positioning needed to score with little adjustment on your part.
Do not always try to stay out of opponent's reach or you will always find opponent out of your reach. Train to slip and bob to stay in range and make the punch miss so you will still be in range to attack. However, do not weave too much.
The power of a punch or kick is at the very end of the arm or leg, so for maximum power, you must have the proper range. The real art comes in catching the opponent at the right time and place when your range is perfect for your chosen attack. It is like catching a bus. To get on the bus, you have to coordinate things so that both you AND the bus are at the station at the same time. When sparring, both of you are on the move, so achieving the right range at the right time takes timing and finesse.