On preparation...
It's just so obvious that a little preparation can go a long way. It's just so hard to always set aside time for doing so.
My most recent example is the house purchase (we're moving in on Dec. 16th).
Tamar saw the house on the Friday before Yom Kippur and decided she liked it. Though I hate to admit it, I spent about 65% of Yom Kippur preparing my negotiating strategy. In brief, here it is:
As I thought about my offer for your home, a few facts have entered into my consideration that I’d like to share with you.

The market is plateauing. If you’ve spoken to agents who know the area, they’ll tell you that. My wife and I have been in the market and there is inventory now and it’s been sitting idle for multiple months. (Yeatman, Claybrook, Kemp Mill Road, Monticello).
We’re at the end of a 9 year run up on prices and there’s certainly the possibility of a dip in the market for the short-term.
Interest rates are headed in the wrong direction. Fewer buyers are going to be able to afford your price as time goes on.
Finally, as you know, fall is not the best time to sell, as more people buy in spring and move in summer. Interest will probably not be as high now as later.
And though I'm not a master, I kept hammering away on these points and did knock $20k off the price in 1.5 hours using that approach!

Anyway, the point is, I thought about it, prepared, and it paid off.