Size of Bass traps

[Termdj]

I'm plunging into unknown territory....I'm busy with the planning/building of acoustics for my cinema room, but I need some advice. I went through alot of threads regarding the acoustics, but when it comes to the bass traps there is a bit of a grey area for me... What size must the bass traps be? Some say that a bass trap per corner on the floor in each corner and some say bass traps in all corners at the ceiling and floor corners...then some say to put a panel from the floor to the corner...I'm not sure which way to go. To build a panel to go from floor to ceiling will be a easier option as i have to import the bass traps as we can't get it locally here. I can get the necessary material to build the panels, but also not sure what the width must be...Any help/suggestions?