flyers do actually work... think about it this way... with pretty much any ad, you're not going to check further into it the first time you see it in most cases... the trick is... make sure your logo/image is consistant...one flyering session in itself might only get a few extra people to your show, but if people are really digging your music, then over time they will get that image of your logo/image/band name ingrained in their head... There are a few bands around Vancouver that are like that for me.. They aren't that big in terms of fan base, but I see their posters all over the place, all the time, so I know who they are... if I don't have anything else to do and have a few extra bucks to kill, I'll see that x band that I saw a gazillion times on a poster is playing and my curiosity gets me. And there are plenty of bands in Vancouver, even really awesome ones, that I only find out about solely from myspace... If I didn't happen upon their profile, they wouldn't exist to me. Now, I'm openly seeking out bands from this area, since I'm in a band, and I want to have as many contacts as I can...the average person, probably wouldn't go seeking anyone out, unless there's already a bit of a buzz around them. People will only know about you if you tell them, and you saturate your area with your music/band name/image/etc... It's a very subliminal thing, and over time if you can imprint you in their subconscious, you'll have MUCH more success getting people to come to shows.
With that said...
Absolutely myspace. Whatever anyone says, it's still a great tool to get your stuff out to people, even locally. Be in contact with a lot of people locally on a regular basis... be very approachable and actively seek out more possible fans... even if it's one by one... at a certain point, word of mouth will start to take over, once your fan base builds up, and believe it or not, you can make dozens of fans from even one single fan if they really believe in what you're doing.
radio promo couldn't hurt. Contact college stations in your area, or better yet specialty shows that specialize in the kind of music you make. Since Clear Channel owns the world, it's not so much of a reality that you'll get some promo on a commercial station unless you have some money to bribe the right people, or you're signed to a big enough label that can bribe the right people to get you mentioned... anyway, develop relationships with radio people.
Go to other shows, even big fucking stadium shows with some sort of promo material...whether that's promo CDs (could get a little expensive) or handbills... spread the word to people...talk to people (don't just hand them out..actually try to converse with them) some people throw away handbills, but you'd be suprised how many people come home in their drunken stupor and when cleaning out their pockets a few days later say hey..what's this...and will check it out.
Simply just talking to people and going out to socialize on the town when possible is great promotion...go to club nights, go to shows...talk to people, be outgoing... any moment you could make a new fan, or intrigue someone enough to check out the show.
and....with that said.....
the last point...
do something interesting. Make your promotions stand out from the crowd. Too many bands just allow themselves to rely solely on convention. Even if you do extreme music like black metal or something, just going with the usual fare for image without any attempt to make it your own, will just blend in too much with everyone else...
what's your schtick... if you don't have one, get one. No matter how much about the music it is, you need a schtick. That can be how you handle PR, or your image, or maybe even unusual musical elements... there's a shitload of people doing the same stuff as everyone else out there, and very little of them will go anywhere beyond the garage, unless they have a great deal of money to throw around.
Controversy is good... if you can find it, go with it, embrace it. OF course, if you do some sort of religious music, or very accessible mainstream music, that might not work AS well without the help of a really clever PR person, but hell, controversy (pissing people off, shocking them, being a regular menace to society) couldn't hurt you... it'll at least get people coming to the show out of curiosity...and once you have them captive, if you're music holds it's weight, you'll make new fans.
and really, nothing is going to work significantly unless people like your music. Don't let small crowds tell you whether or not people enjoy your music, of course, though. Even the biggest people on the planet have played shows in their careers to 4 people and the other bands at 1 am on a weekday making chump change... but the difference between those people, and the average failure of a musician, is they just realize that there will be downs and ups, and no matter how hard you get your face slammed into the asphalt (and believe me... you do...big time) you just dust yourself off, give a big middle finger to everyone and keep doing what you're doing, without giving up..... On average it can take bands 5-10 years to make something of themselves, and that's the best way anyway...since if you build your fan base slowly and steadily, you will have much more diehard fans, than if you just blow a cool million on promo, make it over night and then fizzle out 2 weeks later.
Play as many shows as you can, even for free. If they want to book you, play. The more you play, the more people will see you, and if they like your music, the more they'll want to keep coming to see you. Even if you play a show for 1 drunken fool in the back, that one drunken fool could end up coming to every single show, and even get all of their friends turned on to your music (my band has gotten more fans via word of mouth than any marketing we could have done)
Maybe it's not the perfect advice, but hell, there was a time or two where my band was booked at a very inappropriate venue, and we didn't realize it until arriving. We set up to play, and they of course acted like fools (more used to singer/songwriters and other soft fare) so, we acted like absolute idiots and pissed everyone working there off, caused a big scene screaming back and forth with the owners from the stage, getting the cops called... but we got a fuckload of people off the street coming to see what the hell the spectacle was... they even tried to cut the PA...which I walked up to, flipped it all back on, turned it up really loud while the rest of the band played. We could have been timid about it, or just got kicked off stage and looked like morons, but hell, they listened to us before booking us, it was their responsibility... and we used the situation to make some new fans (which we did... this was on a really busy downtown street...so the place was absolutely packed to watch our "performance". The owners of the place were screaming and crying (yes crying...I don't know why), the police cars were outside of the joint (they just told the owners..hey you booked the band, deal with it... but the flashing police lights were a nice touch) We were playing the music hurling filthy insults, taunts, and generally acting like absolute ****s... Where was I going with that... oh yeah... Controversy can generate A LOT of attention, arguably even more than anything positive. We "played" to a full house of people who enjoyed the mayhem (they were walking in heckling the staff and throwing stuff at the bar and all of that goodness), and we made sure to let them know who we were before we turned off our gear and slowly (over the course of an hour) took it off the stage and took off.
but...if you're music sucks... as I said... nothing will really work..so that's the best place to start.