Funny... we had the flatbase discussion only yesterday at the aprés-boarding (to avoid further pettifoggery: I'm aware that COMLPETE flatbase is as impossible as drawing a PERFECT straight line, even if you use a sharp pencil and a ruler, but I guess the intention of the OP was not to discuss physics
). So for the purists: lets assume that if I use the term "flatbase", I mean as flatbased as physically possible with a moving object on a never complete even underground
A guy of the pack (riding a Custom X) stated he never flatbases, cause it's too dangerous whereas my husband claims to do it very frequently, no matter what board he's riding (both are riding 20years and ride like hell). I assume, they know what they're talking about and the quintessence for me is, that its a very personal decision.
I only flatbase longer stretches since this season (my 10th season in this resort). Never trusted the camber boards I rode so far enough. With the Flagship I ride now (its said to be a hybrid camber but actually its just flat between the feet
) I gradually got closer to flatbase longer stretches, cause it simply gave me the feeling that it's ok to do so. I guess, the board shape is an important variable. Sure, an expert might be able to savely flatbase every board, but thats again a puristic discussion.
You shouldn't force yourself to flatbase. I'm not good in giving technical details... it should FEEL ok to do so (yeah... women and feelings, I know
) Began with only several meters to sound the reaction of the board and gradually increased. Now its about 20m flatbased - little adjust of direction - flat again. Always riding low and centered and very concentrated, feet relaxed but ready to react immediately, reading the terrain well in front of me and prepared to put a little pressure on an edge if the terrain changes. I only do it on runouts with good sight/overview and flat non chopped up snow to gain speed.
Take it easy and dont rush.