In this article, I'll show some quick tips to make working with Final Cut Pro X transitions quick and easy. This article is based on the Final Cut Pro X version 10.0.6 and over. Some features may not appear in earlier versions.
Final Cut transitions are accessed via the Transition Browser. In the media browser buttons, the right side of the toolbar, the center button opens the Transition Browser.
To make this easier, use Option-Command-K to open the Commands window. Type the word 'transition' in the top right search field. You'll see two commands in the center list: Add Default Transition and Show/Hide Transitions Browser. Click on the 'T' key in the keyboard above it, in the Key Detail pane you'll see all of the options available for the T key. Option is unused, so click the Option Button above the keyboard layout. Drag and drop the 'Show/Hide Transitions Browser' command onto the T key. Click the Save button at the bottom right. If you haven't already, you'll be prompted to create your own custom keyboard layout. Now Option-T opens the Transition Browser.
You will obviously end up with more third party transitions and hopefully a good number of your own creations eventually. They are all in Collections, that are the list on the left side of the browser. When you create your own in Motion 5 and are prompted to save, assign it a Collection name that will be easy to recognize.
If you need to find a transition and can't remember where it is, type in the search field at the bottom of the transition browser. The search is a live update as you type each letter.
When you find a transition, you can preview it by clicking it once then slowly dragging your mouse over the thumbnail in the browser. A preview will show in the Viewer. You can also simply hit the spacebar and it will loop playback for previewing.
There are several ways to apply transitions. The first method, grab a transition thumbnail in the browser and drag it onto the edit point in the timeline.
A faster method is to click the edit point to highlight it, then double-click a transition thumbnail in the browser. If you don't have 'handles' or enough unused media in either or both clips, you will be prompted to do an Overlap, which pulls one or both clips closer together so there is enough media to cover the transition. Remember, a transitions adds to the duration of all clips involved.
You can also highlight one or more clips then double-click a transition thumbnail to apply it across multiple edit points at once.
If there is a transition already in the timeline, you want to reuse we have two options. Select it, use Command-C to copy it, select a new edit point, use Command-V to paste it. Or you can Option-Drag a transition from one edit point to another.
Command-T inserts the default transition to a selected edit point. To change this, in the transition browser, right-click a transition and select Make Default from the pop-up menu. To see which is the current default, clear the search field, in the categories column select ALL. The first one listed is the default.
To customize a transition, right-click its thumbnail in the browser, then select Open In Motion from the popup menu.
To apply a video only transition you much either use Expand Audio/Video (Control-S). Then select the edit point and use Command-T or drag and drop to apply the transition.
For audio only transitions, if the are connected clips use Command-G to place them in a Storyline, apply your transition. If they are part of a video clip, Command-Shift-S will detach them, then put them in a Storyline, apply transitions.
There are a whole other group of techniques for adjusting transition that space won't permit here, but you can find out more in Michel Whol's Final Cut Pro X video training here at macProVideo.com. I hope these techniques shown here help you move through your edits more quickly and easier.