i am performing at a coffee shop near me.
most of the people there are rowdy people, who are willing to yell out nonsense, reveal the trick, or even snatch things like cards when they're not supposed to.
i have gone through this when i was much younger, in middle school. kids would be snatching things, etc.
any advice, so this doesnt happen again, or i botch an easy trick by mistake.

Look in your other thread for my answer. Sorry, I didn't realize you also posted it here.

if you botch a trick by mistake, then make a laugh about it with your spectators and show them a different one.

Or dont let them know you have made a mistake, recover.

correct, but sometimes, if it's obvious, you can just move on.

hes not talking about himself messing up, hes talking about if the spectators try and mess with his props, dont do what he asks them to, or do anything else to try and mess up his act

stay in control. if you keep them entertained, they are less likely to grab. you also might want to look into non gimmicked or propped magic. ie coins and cards, and perform only those until you have crowd control down. every one faces grabby spectators, if your audience is enthralled and your patter is entertaining this will be less likely to happen. also have some witty remarks...

It all depends on the situation you are in. For me usually I deal with groups of people, the whole group is never rowdy it can usually be traced to one person. If you can find the one who is causing problems early on you can have some fun. Its like the old saying about cutting the head off the snake. I carry 2 tricks that I use and before the person can cause any real problems I put them on the spot. I perform either napkins over the head by greg wilson, or my sponge ball routine which has basic math that is presented in a confusing way and make the spectator feel silly, and give his friends a good laugh. I have noticed that when I do this the instigator usually gives up, but on the off chance he doesn't I just finish my trick and move on in a polite way. The fact is some people cant stand being tricked. If you have to go to tactics like this you never want to be to cruel to anyone with a trick you still want it to be fun.

hope that helps a bit.

When I was about 19 I did both magic and escapes. I had a subtrunk that I build and unless you knew the secret you could never get out.

I was performing a school show. I started out and performed a trick. A very loud kid yells out... I know how that is done. I smile and say, "so do I" and continue with my show.

The next trick he gets louder and more obnoxious. I politely ask him to be quieter so the rest of the kids can hear and enjoy the show.

The next trick... SAME THING...only more obnoxious. I can see he is going to be a problem.... so I invite him up to "assist me". I pulled out my subtrunk and had him pound on the sides. I had him pound on the bottom. I had him go inside to pound on the inside. I put the lid on and had him pound on the lid from the inside. I promptly locked the trunk and drag it off stage. I threw the keys at the teacher and said, "When he starts to behave let him out, will you?" I smiled and gave the teacher the head nod to go ahead and open the trunk as I went on to start my next effect.

THE AUDIENCE WENT WILD.... I HAVE NEVER BEEN CHEERED LIKE THAT IN MY LIFE!

I never did use that subtrunk for the rest of the show. The teacher took the kid out of the box and told him to behave and took a back to his seat.

After the show the kid thought I was the greatest thing to ever enter his life. I made him the "star of the show" by locking him up and pushing him off stage.

Today, I would probably get sued over it, but it was one of my fondest memories of performing magic... his too I am sure.

Practice in front of a mirror and learn the moves before you show the effect?