When planning a surprise, take into account personal hygene not just yours but everyones' who is involved.
I was planning on doing a large surprise for my wife. I had it all planned out and I had spent a ton of time getting it all together.
I had the plan scheduled to the minute, and any changes would destroy the whole day. It was perfect...or so I thought.
What I didn't consider was how long it would take everyone to get ready for the day. I got ready with plenty of time to spare, I was ever able to motivate my wife to get ready in time without ruining the surprise.
But there were other people who needed to get ready as well and they took their time. And so I saw my surprise crumble around me because it took some of the guests too long to get ready.