Not in the same league as you amazing party people, as my "party" is usually just me and my husband, and sometimes my mother-in-law, but I felt these tips might be useful anyhoo:
Tip 1) Be more generous than I think with how long something is going to take me. I used to end up stressed in the last hour or two, running around like the proverbial headless chicken and scrapping plans left and right because there wasn't enough time. Now I budget generously and, at least at my last party, I made it with time to spare. What a delicious relief that was!
Tip 2) Enjoy the preparation time, not just the party! This was a revelation to me. My mother-in-law loves to be involved in ANY kind of prep, she is just a born helper. Well, for my Sherwood Forest party I made meringue mushrooms, and she popped in a few hours early, while I was making them. Normally, I would stress and say come back later, I'm not ready. Instead, with her help, the pre-party started. She helped me assemble mushroom caps and stems, we giggled, we got chocolate all over everything, and really had a blast! Plus, the mushrooms turned out really great! These are the moments, people, this is life. Don't let it pass you by!