What do you want people to remember about this experience?
This question is always the best place to start the planning process because it creates focus on specific elements, and helps simplify everything.
Any event can look like an overwhelming, daunting task; but if you break it down to the desired memory (or memories), clarity happens. An experience is two-fold: what is happening NOW in this moment, and remembering that moment.
Whenever I am creating an experience, I look at each experiential aspect and ask these 2 questions:
"What do I want someone to remember about this?"
"How do I want someone to remember this?"
Physically, memories make your brain release the same chemicals that it did when you made the memory, just in smaller amounts. For happy memories, these chemicals make you reminisce and give you the warm and fuzzies.
Next time you're planning a little shindig, try tossing in a simple experiential element that you want people to remember. Guaranteed the next time they see you, it will be the first thing they remember.