Don't write action scenes. Write suspense scenes that require action to resolve.

Hey good thoughts on why sex scenes are mostly boring in movies (yeah off course not when it concerns that other kind of cinema Billy):

Ahem. No, this is probably because, personally, I find the situation of two people who want to sleep together but don't or can't far more interesting a story dynamic than consumation. This is an odd admission, but for me almost all film sex scenes are boring as dirt. The conflict is (at least for this scene) closed, so we're going to muck around in soft-focus denoument for five minutes? If the the entire thrust of storytelling is conflict, and both characters want the same thing (to have ze sex) ... you get my point. The only interest in a film sex scene is when chemistry trumps structure.

And there's even more good John Rogers advice about how to write interesting action scenes (plus a good analysis of why The Matrix works, check the post):

Tossing aside all the bigger philosophy, here's my attack: make sure every action sequence has a separate goal within the sequence which might legitimately suceed or fail with derailing the movie. Slap a little suspense beat down as your seed, then let your action sequence arrive from the a.) circumstances surrounding the goal or b.) choices of the character.

You can stop reading now, if you just take this away: Don't write action sequences. Write suspense sequences that require action to resolve.

Moving on, and this was beaten into me by the nice Hong Kong humans I've worked with: every action sequence has its own internal three act structure. Objective, complication, resolution. And not only that, but the complication needs to be something which forces a choice on the character, not just a complication in physical circumstances.

It is valid for the complication to be "the odds suddenly become impossible" if a.) the odds are indeed im-goddam-possible in the context of the movie so far and b.) the way the protagonist overcomes these odds is illustrative of the character.