how many times can i use a green visa waiver travelling from uk to usa per year?

Answer 1

Be very careful here. If you travel more than say 6 times per year to the USA they are going to flag you and you do not need that. Several hours in a cubicle being drilled about all manner of stupid stuff to try an elicit a negative reaction. Trust me its easier to apply for a B1B2 visa which allows you unlimited entries as long as its in force, provided you qualify of course. And you can come and go unmolested as long as you want. It costs a little but it saves huge on Hassle.

Answer 2

If you are a UK citizen then you just fill in the forms on the plane and hand them in when you land. You do this each time you go there.