If you are sick of having a document open with the wrong application, hopefully you already know that you can Ctrl+click or right click on a document and select “Open With.” In the pop-up that appears you can select “Other” and then choose an application, checking off “Always Open With.” Then the next time you double-click on the document, it will open in the proper application. But did you also know that you can Ctrl+click or right click on a document, go to the Open With submenu, and hold down the Option key before making a selection? Holding down Option will mark that application as the “Always Open With” application for that document.
Related: Set TextEdit As Default App to Open Word Docs, Search To Open, Quick Look in Open Dialogs, Quit Applications Without Switching, Using TextEdit to Open Microsoft Word Documents.

Thanks, Gary! You give such great tips! I noticed when I held down the Option key that a couple of other items in the contextual menu changed also. One changed “Quicklook” to a “Slideshow”, for example, and “Get Info” became “Show Inspector”. Question: I sometimes have duplicate apps listed in my dropdown menu (like an older & newer version of Firefox, for example). Is there a way to get rid of items?
I saw one of your vids on changing commands in the Menu bar menus in iMovie by holding down different keys. Could you please consider doing a segment just going through the menu commands in Safari & iTunes, demonstrating what they do and how they can be useful?? This would be really helpful for Firefox & Chrome, too, but I know you stick with Safari for your browser tutorials. Could you also demonstrate the usefulness of apps like Safari Stand and Glims? Thank you!
See: http://macmost.com/forum-how-to-clean-up-the-open-with-right-click-menu.html
Thanks for the suggestions.