If you are in the correct fit, your should feel comfortable wearing the boots without the need to wear them in.
Checking the fit for length
Check the heel to ball fitting of the foot inside the boot, by feeling where the ball of the foot is. The big toe joint should be sitting in line with the widest part of the boot.
The foot breaks or flexes at the ‘ball’ when walking or running, so the well fitting boot should ‘flex’ at this point in the shape also. If the joint is too far forward, the boot can narrow before the foot does, thereby constricting the toes. Such poor fitting can also lead to the soles scrubbing out at the toes
Checking the toe room
The rule of thumb is approximately a thumb width between the end of the toe and the end of the boot. Check the little toe carefully. It has an important role to play in balance and walking and needs room for mobility
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.
Checking the heel fitting
When walking in the boot the heel should rise slightly. This slippage will diminish as the sole becomes more flexible with wear.
If you are in the correct fit, you should feel comfortable wearing the boots without the need to wear them in.