Checking the boot for width
Draw the thumb and forefinger across the top of the boot from the big toe joint to the little toe. It should be firm enough to be neat fitting, but not so tight as to risk pressure or distortion of the foot.
The instep should be neat and firm. If the width is too tight over the instep, but the length is correct, an increase in width is needed.
If the width is loose over the instep, it will crease heavily and allow the foot to slide forward & the toes may hit the front of the boot.
The leather in the uppers will not “stretch”. This is a common misconception, the most that can be said is that they will ‘ease’ a little with wear and mould to the foot.