There are really two roads you can follow.
The "correct + good for your overall chess" way (IMHO :) ) is to mix your diet of blitz with lots of slow games with sound openings that will work no matter the time control. Also helps to play blitz with a 5 second delay to force you to win with clean chess and no race-condition monkey business. The best blitz players in the world are the best slow players ... you'll rarely find an exception to that.
Of course, there's the other way of going about your blitz preparation : If you enjoy the thrill of random moves, surprises and race condition flagging, then anything tagged with the words "unsound" and "gambit" usually do the trick.
You'll want openings that take you quickly into tactical minefields where dragging your opponent to unknown territory and psychologically terrorizing him usually is the need of the hour.
The dubious (?) book Blitz Theory by Maxwell lists a pretty neat opening repertoire for the blitz chess hustler.
A few examples (that the book mentions plus a few that I read elsewhere)
White 1. e4 with :
vs. e5 : 2.d4 with a danish-goring complex
vs c5 : 2.d4 with the Smith Morra gambit
vs c6/e6 : Try the 2.d4 d5 3.Be3? diemer-duhn and alapin-diemer gambit formations (not sure if those are the exact names)
vs d5 : 2.d4 Blackmar-diemer
Black:
vs 1.e4 : 1...d5 : Play the Nf6 Scandinavian
vs 1.d4 : Try the budapest or the baltic defense
Once again .. very few of these openings actually hold water against strong opposition (a lesson I learned after 4-5 years of monkey business) so if your crystal ball has you playing OTB tourneys against 1800+ players in the distant future, you might as well study the cleaner stuff and not have to re-learn a brand new repertoire all over again when you're ready for serious chess.
Am new to blitz games but have found them riveting and much more enjoyable than the usual correspondence games I play.
I've been studying dome openings for white (Halloween and Danish Gambit) which are working just fine.
However, i find that when I go black I struggle. My instinct is to go Sicillian and defend but I almost always get overrun.
Could someone offer a bit of advice as to how I should approach a blitz game when playing black. I would consider myself a fairly adventurous player so not too worried about shutting up shop as black.
Any pointers or particular defences to study would be greatly appreciated.
Thanks