How To Play Blitz

Hi, 

I am playing in Blitz 5 minute competition, 11 rounds over 4 hours. I was wondering if there was any key pointers about playing blitz otb?

I have a medicore rating of about 1500 and will be playing some Fms and IMs in the earlier rounds as i will enter the open division to gain experience. some tips would be appreciated! 

If results are really all that matters then an often heard advice for blitz is to have a very narrow and slightly obscure openingrepertoire and then practise that over and over. (For example online) To get familiar with the tactics that tend to arise. Which will in turn save you a lot of time on the clock.
Other then that you have to accept that you can't calculate much in blitz, will play far from perfect and you're basically looking for cheapos all the time.
Being physically fit is then very important to have the awareness and reflexes. (While at standard you can pretty much still calculate and doublecheck your way to half decent moves even when you're "off" but in blitz it's really going to hurt.) 
Attack. In blitz a well known saying is that attacking costs less time than defending.
If you succeed in all of this, tell me how! I'm a terrible blitz player myself and relatively way better at standard.

Ofcourse titled players are unbelievably strong in blitz and I would mainly be hoping for a great learning experience and a lot of fun, but anything's possible.