Mispriced companies are rare diamonds in the stock market's rough. If you want to find them, you'll have to search through a whole pile of rocky rejects first.

That's why every member of our Motley Fool Global Gains research team has to present one new stock idea to the rest of us each month. While the ideas we like best end up becoming official Global Gains recommendations, we've passed on a number of promising companies, waiting for either a better valuation or greater certainty regarding an aspect of their business.

Below, I've listed two of the companies we're still mulling over, along with the reasons why they intrigue us. If they sound good to you, consider adding them to your own watch list as well.

Makita (Nasdaq: MKTAY)
Potential investment thesis: This well-run maker of high-quality power tools has a revered global brand, and it's trading at a valuation that prices in just 4% to 5% free cash flow growth over the next decade. Given global infrastructure building plans, the company’s best-in-industry balance sheet (more than $1.1 billion in net cash), and its proven sales networks in emerging markets such as Eastern Europe, Southeast Asia, the Middle East, and Latin America, Makita should perform substantially better than that.

Potential points of failure: As a premium brand, Makita could lose business or pricing power to lower-priced competition, particularly in China. Infrastructure spending also depends on government spending, which may or may not be in the cards, given the state of sovereign balance sheets. All told, this is a competitive space, with other players such as Black & Decker (NYSE: BDK) and Bosch, as well as a cyclical one. That's not a great combination for prospective investors.

What we're waiting for: Given the still-uncertain outlook for the construction sector, and Makita’s greater-than-60% revenue exposure to North America and Europe, 4% to 5% annual free cash flow growth for the next 10 years may be optimistic. I’d like to get a better price on the shares.

Core Laboratories (NYSE: CLB)
Potential investment thesis: As global oil and gas consumption continues to increase, and E&P costs keep rising, energy companies will seek to improve production efficiency. Core Laboratories' reservoir description and production enhancement products and services are the most advanced in the world, helping clients determine the best way to drill a well to increase the recovery factor beyond the industry's dramatically low 40% average. No competitor can boast similar size or scope, and Core Labs should see healthy growth as energy prices rebound and E&P companies invest in growth.

Potential points of failure: Core is only brought in after oil or gas has been discovered and is ready for drilling. If a decline in energy prices or exploration slows drilling, Core will suffer. Furthermore, any countries that proceed with drilling bans in the wake of the Gulf of Mexico oil spill could also hurt Core's prospects.

What we're waiting for: Unlike many energy industry stocks, Core Labs is up more than 30% this year, despite all of the headwinds facing the industry. That means there are now some pretty aggressive growth expectations baked into the price of the stock. Before buying shares, I’d like to see more news from E&P companies and potential core customers such as Chesapeake Energy (NYSE: CHK) about their drilling schedules and capital expenditure plans.