This is something I get asked ALOT...and probably something I take for granted as I could probably do it with my eyes closed!
Whenever I've taught workshops or been sewing on my instagram stories people ask how I tie the knot so quickly so I thought I ought to put it here in concrete. It's nothing fancy but just a method that has been passed down through my Mother's family, it may be the same way you do it too.
Lick your index finger
Pinch the thread between thumb and fore finger
Wrap thread around your finger
Roll finger back over your thumb to twist the thread together
Clamp the thread on top of your thumb with your middle finger nail (gently!)
Pull the thread away with your other hand
Get practising and let me know how you get on!