Now I'll be the first to say that in-person is better, you'll find more attractive women, they're usually more likely to actually want to meet if you did a good job, there's less competition, etc.
That being said, OkCupid can be a fun resource for newbies and/or every few months as you go through and go after the very few hot ones. My game has been lagging lately for a reason I can't quite figure out yet, so I decided to perform an OkCupid experiment, just to see if it generated new leads in my preferred target demographic (girls under 27 (I'm 29) who don't want babies tomorrow).
Oh boy, is it.
First off, I replaced my main picture (leaving my other pictures intact) with a picture of a waving grizzly bear. I'd go with your own animal or character or something to be original. Make sure the picture is both funny and you can pretend it's you. Technically this is a violation of OkCupid's terms of service, but, so?
Second, I replaced all the objective data, "This is who I am, this is what I do, blah blah blah" - basically any seriousness in my profile at all with a sarcastic rewrite. For example, instead of saying, "I'm athletic, I do Crossfit and lift multiple times a week", I'd replace it with, "I like to pick up heavy things and throw them on the ground, repeatedly. I'd also like to take steroids eventually". I also specifically wrote about how I'd be targeting younger girls, and said older girls all wanted babies tomorrow. That should reduce the response rate from girls who want to settle down and have kids, and increase it from irresponsible cuter younger girls. Perfect.
Third, I targeted girls in my preferred demographic (18-27, though I initially started with 18-22, where I also had great luck), saying absolutely childish insults. I would start off with, "You're a dork", or "You have cooties" (this one is particularly good if you're sending a new message to a girl who didn't respond before, FYI).
I decided to test this after reading this:
http://heartiste.wordpress.com/2014/08/02/toddler-game/
After trying this, my response rate has been quite high (the highest I've seen on the site - and I've used an account on and off since 2008). It gives you a lot of options - I've played off being a bear for real, I've started insulting the girl with an even more childish litany of insults (poopeyhead seems to work too).
Basically, at least when going after younger girls (though my suspicion is that older girls work similarly), treating them like they're 8 years old and you're about to pull their hair on the playground and having funny pictures seems to be just about all you really have to do.