Managing portfolio investments over time - signals, intuition, strategies?

Something I've been thinking about for a while: once you've got a portfolio ticking along, monthly contributions going in, tracker funds doing their thing, what do you actually pay attention to beyond that?

I'm mostly passive but I find myself occasionally second-guessing allocation when macro stuff shifts. Curious whether people here actively watch things like gilt yields or just ignore it all and rebalance on a schedule, even if thats once a year. Do you have a cash buffer target tied to expenses, or just keep it fully invested and accept the volatility?

Not looking to day trade, more interested in whether there's anything systematic people do once the boring foundation is in place.