Last week I was called to collect a swarm at Haywards Close, Wantage, England. By luck the swarm congregated on the lower branches of an apple tree which had a wall below it. To add to my luck I had my camera with me and started filming the swarm; starting from it being a cloud of bees to a couple of balls on two branches of a tree. See link https://www.youtube.com/watch?v=DCVRYW2OIbg
I was able to place a nucleus box on the wall and cut the branches the bees were on into a box. I gave the branches a bit of a shake and the hard part was done. Patience was required to ensure the bees were happy in their new home and the majority of the flying bees were in the box. Just after sunset I moved the nucleus box to my apiary.