Look at the big picture. Whether you're investing everything together or choosing to maintain separate investing accounts, it's a good idea to view your financial picture as a whole.

If you're just starting out together and you decide to put your individual assets in a single brokerage account, you'll probably need to rebalance your joint portfolio. Combining your investments creates a new big picture, one that might be overweighted in some areas and underweighted in others. For example, different mutual funds can invest in the same companies or sectors. This might lessen the diversification in your joint portfolio and compromise your protection if a particular company or sector drops.

Similarly, if you both work for the same company and both hold a lot of that company's stock, you may want to consider selling a portion of that and diversifying into something else.

If you invest separately, it's still wise to periodically view your overall asset allocation -- all your accounts together, including your retirement accounts. Ideally, you want your investments to work together, while avoiding extremes like having one overly aggressive account and one totally conservative account. As you look at your big investment picture, make sure that 1) your individual accounts reflect your personal investing styles and make good sense as stand alone accounts, and 2) that they work together to meet both your individual and shared goals.

Reviewing your accounts in the context of the whole will also help you make rebalancing decisions as the markets or your goals change.

-- Realize that commingling your assets is "forever." This is an important concept, especially when it comes to an inheritance, because once you commingle your assets in an account, it's extremely difficult (if not impossible) to separate them out. For example, I know a woman who inherited some money from her father. Without thinking too much about it, she put it in a joint account with her husband. Now she wishes that she had kept it separate, not because she's even remotely considering divorce or because she doesn't want to share it with her husband, but because she feels a personal tie to her father's legacy. With the money in a joint account, she doesn't have quite the same autonomy.

Talk and share your plans for the future.

There's no right or wrong way to marry your finances. But like anything else in a relationship, it requires some give and take, some trust and tolerance. Use the New Year as a motivation to look at what's most important to each of you and refine your goals and your shared financial plan. If you talk honestly about your feelings -- towards money, investing and your dreams for the future -- it will be easier to come up with the best way to make those dreams a reality.