1) Always smile. The coach is looking for someone with a lot of school spirit. Think about what the squad looks like when performing. Do they have frowns on their faces?
2) When chanting, be loud but don't scream. There's many people in the audience, and some might be chatting with one another or yelling "GO (team name)!!!!". But the point is, the cheerleaders need to be loud or else no one can hear them.
3) While you're waiting to try out you should stretch and make sure you're ready. Did you notice the flyers sometimes do a needle or scorpion while in the air? And the other cheerleaders do toe touches and backbends a lot. Make sure you're ready to perform these to the coach.
4) Keep your hair in a ponytail or bun. I've had experience with doing sports with my hair down, and it is not fun. If you have your hair down you may focus more on that than the cheering itself.
5) Look nice but not fancy. What I mean is don't wear your clothes from 2009, but don't buy a new outfit either. Also, don't wear a fancy dress, obviously. Wear a t-shirt, with (preferably matching) shorts(not denim), sweatpants, or stretchy pants. Do your hair decent too, don't make them think you just got out of bed. It may help to wear your team colors (if you know what they are). This is probably the least important tip, but it shows respect, and will surely give you a better chance than the girl who wears a yellow shirt full of chocolate stains and light blue shorts.
Hope I helped, and good luck making the team ????
Smile smile smile smile never stop smiling! Be confident and really peppy and happy because that's what teams look for in a good cheerleader. If you mess up on something just laugh it off, don't look like your life is over because they'll see it and think that you're not what they want. When it comes to tumbling, throw whatever you can, if you just got a back tuck or something, throw it. Good luck, I hope you make it!
Prepare: Get the information of the place, time, and date of the tryouts
Attitude: Smile and be yourself
Presence: Make an effort to talk to others trying out, show your are a team player
Be Presentable: Wear comfortable, movable clothing to tryouts (http://www.livingcheer.co.uk/)
Just make sure that you know your routines. Being nervous is normal but you have to overcome that. Shout out and that will help.