A portfolio you can explain in one sentence
Global stock index fund, a bond index fund, and a cash buffer. That's it. When I had eight positions I checked prices daily; with two I check once a quarter.
The rule
Target 80/20 stocks to bonds. Rebalance only on the first trading day of January, and only if either side drifts more than five points. Writing this down ended the monthly "should I" conversation with myself.
What I gave up
Any chance of beating the market, and any chance of badly trailing it. For a plan measured in decades, that trade is fine with me.