Probably the most cliched and pointless of all the well trodden ways of attacking a Best man's Speech is to spend a huge chunk of the speech talking about being the best man. For me this is about as close as it gets to admitting you simply couldn't be bothered to really think about the best man's speech and just decided to go for filler instead of killer. If at this point you're thinking 'well all the templates I've seen online talk about being best man!'...yes they do. They also have some of the worst one liners, jokes, conceits and layout of any speeches known to man.
The basic idea of a best man's speech is to talk about the groom, not about you. It is after all his big day not yours, and your job is to celebrate him and his new wife, be as funny as you can and chuck in some genuinely heartfelt sentiment. You've only got a maximum of ten minutes to get the job done and wasting time going through the various ins and outs of best man duty is about as counterproductive as it is funny. The worst part of all is that anything you're likely to say on this subject has undoubtedly been lifted from a template and heard a million times before. And it wasn't that funny the first time around.
This whole approach stems from some best men approaching this speech as if they're a budding stand up comedian. Stand up comedians talk about themselves constantly because that's their way of introducing seemingly real and funny observations about the world. They want to project a humorous take on something by using themselves and that's fair enough. Best men are not stand up comedians, some might think they are and you can usually tell them by the over zealous rapport they try to build with the audience. Yes, you should engage, excite and at times communicate with your audience but in a warm, gentle and sincere way; not mic in hand firing off one liners and waiting for the applause. Anyway you have a ready made source of material that needs no introduction: the groom.
If you're talking about yourself then you've run out of ideas. If you've run out of ideas then you're not thinking hard enough. If you really want to kick things off in style then a good place to start is by visiting the Best Man Speech Opening Lines page and discover other ways to achieve victory.