Bracing a deck

Hiya , looking to get a bit of advice on how to brace the posts of a deck . I have recently slightly extended a deck where the decking boards are just over 2m off the ground . Problem is the original posts and the new ones dont align due to the terrain ( infact the old posts dont align either ) . When i say align i mean they are not able to be braced with a piece of wood as they are offset from each other . Is there any other way that I could brace the posts ? a friend did suggest metal straps , the ones with a ll the holes in , not sure what they are called..any help more than welcome please

How about a wire (stainless or otherwise) similar to that shown here: I can't help thinking flat strapping will look fairly mediocre.

For a heavier brace than sugested above, you could use M16 Rod from Big Gee.
Or perhaps you can just nail some speedbrace to the underside of the joists. This may stiffen the structure without bracing the posts, depending on your circumstances.