I remember visiting this website once...
It was called Stephen Amell: What To Expect In 'The Flash' & 'Arrow' Crossover Episodes | Access Hollywood
Here's some stuff I remembered seeing:
Stephen Amell: What To Expect In \'The Flash\' & \'Arrow\' Crossover Episodes
Stephen Amell chats with Access about the success of his F*ck Cancer campaign as well as the upcoming “The Flash” and “Arrow” crossover episodes. What did he find interesting about doing slow-motion acting for the fight with The Flash? Plus, what can he tease regarding the structure of “Arrow” that happens on “The Flash”?