Not sure about Favorite, but LEAST favorite is definitely E-mail, and in a way, also the internet...
The reason being that most professionals now a days have to lead a 24 hour lifestyle just because information can be sent to one another with just 1 click of a button, and clients definitely know how to take advantage of this...
Like back in the late 80's or even early 90's there was no way possible to basically send a large design floor plan or canvas art design to a client for approval unless you literally snail mailed it to them or sat down with them at a meeting to discuss it... now a days, just zip it up and send it or use one of the million file transfer sites and send it over and sometimes within minutes you will have a reply and its back to work...
The reason being that most professionals now a days have to lead a 24 hour lifestyle just because information can be sent to one another with just 1 click of a button, and clients definitely know how to take advantage of this...
Like back in the late 80's or even early 90's there was no way possible to basically send a large design floor plan or canvas art design to a client for approval unless you literally snail mailed it to them or sat down with them at a meeting to discuss it... now a days, just zip it up and send it or use one of the million file transfer sites and send it over and sometimes within minutes you will have a reply and its back to work...