One of the more frustrating things I experience in daily usage of my Mac is opening a file that launches an unexpected application, which can sometimes result in a failure to open the file. One of the primary examples is when a PDF is created using an Adobe product, associating it with Adobe Reader instead of Mac OS X's built-in PDF reader, Preview.
Luckily if you find that Finder is not opening a particular file type in the proper application, you can change the file associations for all files of the same type. The process is quick and easy and can definitely relieve some frustration when used appropriately.
Let's continue the example with a PDF file (this process works for all file types though). If your preferred application for reading a PDF file is Preview but you've got some PDF documents associate with Adobe Reader or another PDF viewing application, select one of those files and press (Command + i) to "Get Info."
The "Get Info" window is a great resource to become familiar with, allowing users to do everything from changing application associations to distributing permissions changes to customizing icons. For this tip, navigate to the portion of the window marked "Open with:".
Click on the drop down menu and select the program you want to use to open files of the same type going forward. Once you have selected your application, you will notice that the "Change All..." button becomes active. If you are sure you want all files of that type opening in the newly selected application, click the button and confirm.
It's as simple as that! If, in the future, you find that opening a particular file would be better in a different application, simply select that file and change the association for it. Going forward only that file will open in the new program.
What are some of your go-to applications for opening common file types like PDFs? Let us know in the comments!