Gymnastics and cheer gyms have plyo floor
Plyo floor is usually constructed of hard springs, foam, plywood, and carpet. Plyo floors vary in quality from gym to gym. Official olympic gymnastics flooring that competitive gymnasts use is the highest quality and will give you major spring. This is because gymnasts want to do huge tumbling passes. Most cheerleading facilities use a lower quality, more rigid plyo floor. They want the rigidity because their athletes train in shoes and need stability for supporting and tossing the team members up and down.
But it doesn't matter what the plyo floor is... all plyo floor helps you jump. There is no grass or ant hills or moisture or other distractions. It's pure bliss to trick on.
Gymnastics and cheer gyms are everywhere
Cheerleading is becoming very popular and Gymnastics is one of the oldest and most popular Olympic sports practiced all over the world. Just as martial arts has become commercialized by western culture with the advent of McDojos, so to have cheer and gymnastics gyms! Parents enroll their children into cheer and tumbling programs as if it's a daycare service. What this means for us is that these gyms are now easy to find! I've stumbled upon these facilities in some of the smallest towns in rural, bumfuck-redneck Alabama. THESE TRAINING FACILITIES ARE EVERYWHERE!
Gymnastics and cheer gyms have open gym times
However, as a trickster you're inevitably going to want an open gym opportunity so you can train yourself. Open gym just means the gym is open like a public pool: there are coaches around to act as life guards while you play on the plyo floor for a few hours. Yes, Open gym is usually limited to 1-3 hours or so and most gyms only have open gym times once or twice a week.
Some gyms do not have open gym times at all. This is becoming a rarity. Because nowadays most gyms have open gym times for at least their students. They encourage their students to come to open gym and put in additional practice during the week. That's why some gyms only have open gym times for enrolled students. However, I've found it easy to get into these gyms as a non-student, and the staff accommodating to my request. Finally, some modern gyms that are hip with the times, realize there is a humongous money making opportunity if they accommodate parkour and tricking peoples. So they will have open gym times for anybody. However you put it, it's becoming easier and easier to find gymnastics and cheer gyms that will welcome your interest in tricking at their facility.
How to find a gymnastics or cheer gym to trick at
Check your phone book and check online. Ask around. Jot down a few. If your list has more than 3 gyms on it then look on their website for open gym times, or call and simply ask about open gym times. At least one of those is probably going to have open gym times. Make a note of it and go. You're done.
How to worm your way into a gymnastics or cheer gym
If you could only scrounge up 1 or 2 gyms on your list then you need to be more careful... Look on their website for open gym times. If none are listed then you can either risk calling and asking and then getting shot down, or you can be more careful so you can worm your way in. Here's how...
Call first. DO NOT ASK ABOUT OPEN GYM, simply chat someone up on the other line and ask a bunch of questions about the facility and coaches (don't ask about their training programs unless you want to take classes). Ask questions you don't even care about. Just ask a bunch of crap so they become invested in you. Get the other person's name and give them your name. Tell them you'll swing by sometime soon and act excited. Later, visit the gym. When you arrive tell them your name and that you made a call earlier and talked to whoever. See if you can get a tour of the facility. Then after they have invested this much time into you already, pop the question: tell them what you do (say acrobatic martial arts, it's more socially palatable than tricking) and request to sign a liability waiver, pay a fee, and arrange a time to come in during the week to practice your "martial arts" moves (do not say the words "open gym"). Tell them you're experienced even if you are not. They have no idea what you are experienced in or even what that means, so just say it.
Now why exactly did we go through all this trouble? By calling first and exchanging names, we've added some social proof to the situation. It's as if we know somebody who already works there! Next, by getting a tour we've made them invest more time into us as a potential client. They have something at stake now. Finally, by not asking about open gym specifically, and inquiring about waiver and payment we've taken reigns of the situation and have put them on the spot. This makes them more open to cooperation, or at least negotiation. Even if they already have open gym times established this ritual will not be a waste of time.
If all else fails, ask to speak to the manager and beg them.
Don't settle. Keep looking. Even when you found a great gym keep looking, there is always another good gym to train at out there.
Also, for safety reasons, I recommend reading my page on 9 steps to safer pain free tricking and reading my #1 tip on tricking on grass vs. plyo. It's a common misconception that plyo floor is always safer than tricking on harder floor. It's not. When you begin training on plyo floor do not train for too long. When you are highly fatigued on plyo you are at a much higher risk of injury than on harder ground.
And now, finally, if you are a 15-20 year old male, you may be able to find a nice girl at one of these facilities around your age. Acrobatic sports are female dominated. These facilities are often jam packed full of fit, young, happy teenage girls in scant clothing. ;-) And there isn't much male competition at these gyms...