1) Keep taking your Prozac. Most people can trip just fine on SSRI's (unless they also double as 5HT2A antagonists, like trazodone). The LSD's effects will be ever-so-slightly diminished, but better to have an ever-so-slightly weaker psychedelic effect than be in a foul mood from antidepressant discontinuation. You can always take more acid on your second trip if your first one was truly underwhelming.
2) Speaking of which: Ensure an optimal set and setting that works for *you*. While a tripsitter is generally a good idea, some people are more comfortable tripping alone. Some people like the Grateful Dead and mandalas, others ...don't. Many people like to trip out in nature, others have germophobia and could never relax anywhere they don't have a clean bathroom nearby.
3) Make enough time. No, you will not be okay to drive or pretend to be sober in front of your parents after 8 hours. Going into a trip with a set/setting like that is likely to end in disaster. Also: You likely won't be able to fall asleep for 10 hours after taking LSD. So this is not a drug you want to be taking at 10 pm or later.
4) You like weed because it always relaxes you? Good for you, but weed and psychedelics tend to be *very* unpredictable in combination. For some people, any attempt to calm down during a bad trip by smoking weed will just make it worse. Sometimes *a lot* worse.
If you need to take the edge off of a bad trip, take some xanax/ativan/etc. A mild dose can help get a trip back under control without aborting it completely.
