I recently had my first acid trip and it was amazing. It was so amazing because I took it early in the day with three other friends and we went for a walk in the country to get as far away from anyone sober. Since it was early spring all the new buds and flowers etc. looked extreamly beautiful and gave me alot to think about (evolution/life a constant topic). We stayed out til sunset (which looked beautiful) and then went back to our house where we got the lighting nice a low (fairy lights are good) and listened to our favourite music/some new stuff/some cliched stuff (Sgt. Pepper's and Dark Side of The Moon are both incredible). We smoked weed on the come down and it brought us right back up to the peak of our trips. However, don't plan too much as someone else said, you will be feeling very spontanious (though, having pen and paper near by is a must).
Aslong as you are used to altered states of mind you will be fine (I've had a good training with weed XD). You just need to be confident in yourself and have nothing negative going on in your life. You also need to understand that you will be analysing the world completely differently to how you normally do, almost like a child sees the world. You will question everything, sometimes reaffirming your sober outlook, and sometimes smashing the concepts you currently hold.
Maybe read some Eastern Philosophy before you do it (not imediately before you understand, but in the weeks leading up to the trip). Alan Watts' audio lectures are also pretty amazing. The basic teachings of oneness with the world, that we came out of the earth, that you need not be afraid of death are very comforting when tripping. However if they're opposed to your current beliefs (if you are a Christian for example), then the clash would probably too much, and you'd be second guessing you entire belief system (which is not good at all).
I've seen the life affirming nature of LSD and it's incredible. I've also seen someone having a bad trip after she took too much in an environment she wasn't comfortable in and it was horrible, but you have to remember that if it is going bad, you WILL be fine the next day, if a little shaken. If you want a real mind fuck go to a store and buy something when you're still tripping. Interaction with sober humans is near impossible (you forget how to act normal, even though you are acting normal, and the constant second guessing of yourself is a real mind fuck, but it's a fun ride if you like that sort of thing).
The best advise really is have fun and have good trip.
