Try a small dose first. Then work your way forward. Don't try to squeeze your first trip in. If you don't know for a fact that you have the next 8-12 hours to yourself, then don't do it. Any unnecessary anxiety needs to be eliminated. Don't take it on a full stomach, and keep fruits around to munch on if you start losing energy (I love apples on LSD). Music is great, but try to keep it upbeat and energetic. And just remember, don't be afraid. There are no such things as bad trips, just bad mindsets. Emotion and setting are everything. If you're in a tranquil setting, with little to nothing to worry about, and have taken a responsible dose, I don't see what could go wrong.
Don't try to get up and walk around outside if your by yourself. If your by yourself, and it's your first time, you might get lost.