You decide whether you want/need a sober guide if you give it a try. It's great for some people to have a minder, personally I it a bit repressive (even someone else minder). I've had a few chances to try iowaska but there were all these rules involved like having a minder, dressing all in white that just aren't for me, so I've passed.

Know thyself! If you go into it knowing you are going to have a cool time and don't need a minder you will probably do great. Nothing is more true than that the attitude you go into this kind of thing with will usually define your experience.

Limit the variables before you try the first time. Be with a person you or persons you know and care about who care about you. If you have some heavy karma to work out with one of those people there is a good chance that you will be doing that at some point so if you don't want to deal with it find other people.

Nature is great for this kind of thing. The worst random variables are things like police and parents, use nature to separate you from that kind of stuff. Police, parents, heavy trips and most everything else will just pass if you keep your cool, it'll all be over in less than a half day.

Hydrate!