What does last week’s market slide across most of the major asset classes imply for investing? A lot… or maybe nothing. The decision to adjust a portfolio, or not, depends on the risk-management strategy.

Every portfolio needs a clear-eyed plan for dealing with risk—it’s the financial brain that controls the investment body and provides the map for navigating rough financial seas. With that in mind, now’s a good time to review and reaffirm the first principles of enlightened risk management in the care and feeding of conventional investment portfolios.

1. Develop a plan. Yes, that’s obvious, but it’s easily overlooked. Many investors have a general appreciation of the merits for managing risk (as opposed to chasing return) but don’t have a proper plan in place. Vague notions of what you may or may not do don’t pass muster. You needn’t be a slave to rules, but there should be a clear path for traversing periods of chaos as well as calm through time. This includes a methodology for regularly collecting and analyzing relevant data that’s integral to your plan.

2. Recognize that a successful risk-management strategy will be multi-faceted. There are no simple solutions or silver bullets. Instead, there’s a zoo of possibility in terms of risk factors from which you’ll selectively choose for assembling a customized plan. That said, there are two concepts that typically form the backbone of risk management: asset allocation and rebalancing.

3. Notice the limits of asset allocation. Like any one aspect of risk management, this one has flaws. This implies that you should add techniques that compliment AA’s deficiencies.

4. Choose weights for asset allocation that match your goals and risk profile. For what should be obvious reasons, there are no one-size-fits-all solutions here. But there’s an obvious place to start: market-value weights, which offer useful reference points on the customizing journey.