One of the biggest mistakes I've made in the past with regards to miles and points was earning miles without having a definite goal. As shown in the past few years, airlines and hotels invariably devalue their awards programs. For instance, the gut-wrenching changes on some United partner awards which went up by 60-90%.
Similarly, US Airways awards in business class from North America to North Asia were inflated overnight from 90,000 miles to 110,000 miles. While devaluation is an ever-present threat, I believe that certain airlines are much more "due" for a sudden unpleasant shock than others. Here are my proposed top three:
1. The New American: As to be expected, American and US Airways are almost certainly going to consolidate their award charts to make them more even across the board. This is likely to wipe out certain sweet spots like American's 135,000 mile first class award from North America to Asia. As mentioned, US Airways has already nixed the 90,000 business class award to North Asia. When the integration is fully complete, expect other sweet spots like US to Australia and the excellent Caribbean/Mexico/Central America to South Asia redemption to increase accordingly. There's also a good chance that they might just raise the price of most awards across the program, either before or after these theorized changes.
2. Alaska: I've only recently started accruing Alaska miles, but in the past year or so, I've really seen the value of this program. Even though they're not in an alliance, they partner with a lot of airlines I like and you can earn miles on any of these partners for Alaska. In addition, they've recently allowed one way awards using their miles. Finally, there are so many outstanding sweet spots in this program such as 100,000 miles each way for first class in the infamous Emirates A380 (onboard shower time!) and the well-known 70,000 mile first class redemption on Cathay Pacific from North America to South Africa… by way of Hong Kong! With all of these positive attributes to the program, I would not be surprised in the slightest if Alaska's management decides to raise their prices on award tickets.
3. Singapore: Much like Alaska's program, Singapore KrisFlyer has stepped up their game. This was best characterized by recently allowing members to redeem their new A380 suites class awards at the Saver level. The A380 flight from Singapore to Los Angeles by way of Tokyo used to cost over a million KrisFlyer miles. Now it's less than 10% of that total at the Saver level. Unlike Alaska's program, KrisFlyer miles do come with somewhat modest fuel surcharges, but with the combination of the aspirational awards and the ability to book them at 1/10th their previous cost, Singapore looks primed for an across-the-board devaluation.
Obviously, as a member of these programs, I hope I'm wrong on all accounts and these programs don't devalue at all. Of course, that's unrealistic, and instead of hiding our heads in the sand, I think it's a good idea to burn all miles (and in particular, the three listed above) as soon as it's feasible.