Canadian golf legend George Knudson dedicated an entire instructional booklet to the importance of good balance. All good players and top instructors agree that without balance throughout the swing (both physical and emotional) you have no chance of producing good shots consistently.
For good static balance, I suggest feeling your body weight is 50/50 back to front (heel to toe), and 50/50 side to side (front foot to back foot). Assuming you have a correct spine angle at address, your weight back to front will tend to favor the balls of your feet-which is why you need not over emphasize this sensation. Conversely, if you over emphasize weight on your heels, you may lose your spine angle, and this will throw you out of balance to the rear.
The 50/50 feeling side to side is very easy to achieve, because it is, indeed, "just a feeling." In reality, if you have your upper body positioned properly behind the ball, your body weight will naturally follow, meaning your weight will favor your back foot.