i was the 1st thing i was taught at the hospital, and worked wonders, after my section i couldn't really lift her properly, but when she was swaddled (by the nurses) i could just grab the front of the blanket and lift her on to my tummy.
it also helped me with dream feeding, as they were so secure, she didn't take on as much air and burbing could be done without waking, she slept through the night at 5 weeks.
they say it is the action of forcing them to drop their shoulders that relaxes them, and
with my 3 year old, i would still rub her shoulders downward when she is kicking off and it helps stop a tantrum forming and she is starting to calm down.
only advice would be to lay of hats, i see so many people especially on the us birthing programmes who swaddle a baby and then put a hat on it too.