Generally speaking your best bet is probably going to be meeting someone here. People have been successful getting vanilla friends or significant others to play with them, but personally I've always found it to be easier and more enjoyable to play with people who already have an idea of what I'm into and why.
That said, I would poke around here (no pun intended) and see who you can find in your area or whatever area you'd be willing to travel to to meet. Chances are one or both of you are going to want/need some time chatting to get to know eachother. After that once you've gotten comfortable with the idea meet for a non-play date - go for lunch or coffee and see how you get along in person. Once you're comfortable with that, you can talk about getting together to play 🙂 Of course this is just a general outline. Sometimes people do it differently - faster or slower. This is just how I've gone about it in the past.
Another way would be to look in the Gatherings section of the forum and see if there are any munches or gatherings in your area. I think they have occasional munches in Chicago that you might want to think about hitting up. There you can meet people and see if you click with anyone without any pressure. There's also a few annual gatherings that are a great opportunity to meet a lot of really great people all at once. NEST is held the beginning of every May in Philly. Bella's Birthday Bash is every November in Ohio. UNY is held Superbowl Weekend in Albany, NY. They're all great and you'll meet awesome people at every one.
Lastly, you could try the Personals. I don't know how much luck people really have with the Personals section around here, but if nothing else you can get the names of people who live in your area and send them a message. It can't hurt.
My advice on messaging - don't be overeager to ticklechat. It's a big mistake a lot of people make. Some people are really super into it. But many others, especially girls (in my experience) really prefer to get to know you a little bit first before tickle-flirting. Many girls (and maybe guys, too - I'm not sure) will flat out ignore messages that start with anything like, "Hey, where are you ticklish? Do you want to play? Tickle tickle!" or anything like that. Pretend you're walking up to him/her in a grocery store or a bar or in class and strike up a conversation that way. There is a lot more to all of us than tickling. Start with all that stuff and let the fun stuff come up naturally.
Sorry this is so long. Hope it helps! Good luck!