Source: Flickr user Hans Splinter

Although the holidays are cramped for time, making a few savvy moves before the New Year can have a profit-friendly impact on portfolios next year. With that in mind, we asked three Motley Fool analysts to weigh in on what kind of housekeeping they think investors should be doing to their portfolios ahead of 2015. Read on to learn what they think.

Matt Frankel: As the end of the year approaches, you may want to consider cutting your losses on losing investments, even if you haven't sold anything in your portfolio at a profit.

The IRS allows you to use investment losses to offset capital gains for tax purposes, and even allows you to deduct them against your other taxable income if your losses are larger than your gains. Currently, this amount is capped at $3,000, but any excess amount can be carried over to the next tax year.

Depending on your marginal tax rate and whether or not you held your profitable investments for a year or more, your capital gains will be taxed at a rate between 0% and 39.6%. And, if you don't have any capital gains to report, the tax savings produced by capital losses are equal to the amount of losses times your marginal tax rate.

For example, if your marginal tax rate is 28% and you sell investments at a loss of $2,000, it could mean tax savings of $560. In a way, the government is subsidizing your bad investments, so maybe you should take advantage.

Leo Sun: At the end of every year, investors should see if any of their holdings in a single company have grown too large in proportion to the rest of their portfolios. This practice, known as portfolio rebalancing, is basically an oil change for your investments.

For example, a soaring stock's weight over the past year might have caused the investment to rise from 10% to 20% of your portfolio. While that's great news, one overweight stock can greatly increase a portfolio's volatility. Therefore, it can be smart to sell part of the position, take some of the profit, and reduce the weight of the stock to its original percentage of the portfolio. With those profits, you can buy more shares of your portfolio laggards to take advantage of dollar-cost averaging. Selling the winners to buy the losers might feel very unnatural, but over time hot stocks inevitably stall out or decline, while underappreciated losers can suddenly impress Wall Street.

Yet portfolio rebalancing should never be done blindly. If there are catalysts for an overweight stock on the horizon, it might be wise to hold on for a bit longer. It's also important to identify which fallen stocks are undervalued, and which are lost causes to cut loose as tax-reducing capital losses.

Todd Campbell: Reminding investors not to buy or sell their positions blindly is great advice, so I'm just going to add to that suggestion and recommend that before year end investors review every one of their holdings through the lenses of a long term investor.

It's been proven time and time again that investing for the long-haul outperforms short term trading, so investors may want to focus less attention on whether returns are up or down this year and more attention on whether or not the reasons they invested in the company in the first place remain intact.

All companies can struggle at one time or another, but that doesn't mean investors should head for the exits. For instance, long term winners including Amazon, Netflix, and Priceline have had their fair share of drops over the years, but each has proven itself to be a great long term investment.

That suggests taking a hard look at each company in your portfolio and asking whether the market opportunity for its business is the same or better than it was last year. If it is the same or better, it may be worth sitting tight, or even adding to your position, regardless of this year's return.