Whenever things are going really well — as is the case right now on Wall Street and probably in your retirement portfolio — it's only natural to want to leave things be. Why try to fix what's not broken? But even the most patient buy-and-hold investors understand that you must revisit your strategy from time to time to make sure things are unfolding as you originally envisioned. The end of the year, when your thoughts are naturally focused on family, the coming year, and to-do lists, is a perfect time to do just that. To make this process easier, MONEY has put together a checklist of seven important steps to take now before the year ends to set your investment portfolio up for 2018 and beyond.