Updated: Jul 9, 2021
Hand sewing is very important when making coat, waistcoat. if you turn a well tailored coat inside out and examine the sewing around the armhole, and seams you will see that they have stand stitching to flatten and attached by fine stitches. now most tailors use the machine just for the seams and attaching sleeves, but the Tailor's knot, Hand felling, overcast stitch and stacking thread are still being use.
Most tailors are using beeswax with the tread run trough it. some tailors use silk thread. using medium size needle ( not too small not too big) using a thimble to push the needle trough, (wear the thimble on third finger on the right hand) suing a method of see towards you than away form you.