While you do everything you can to take the best pictures possible, it doesn't hurt to have a photo editor or image processing tool to cover situations where details are out of your control. For example, a product such as DxO's OpticsPro can milk every last scrap of information from your RAW photos and produce high quality output. For a limited time, you can grab this program free.
Until the end of the month, you can pick up a product key for DxO OpticsPro 11 Essential by visiting a special promo page on the company's website.
All you need to do is enter your email (and make sure the "send me junk" tickbox is unchecked) and you'll receive a download link and serial number.
You'll have trouble finding references to OpticsPro on DxO's website, because it was replaced by a product called PhotoLab. Even so, the program is incredibly capable and packs the following features:
Note that this free version can't be upgraded later on, so if you actually want a copy of OpticsPro's successor, PhotoLab, best to check out pricing and features on that beforehand.