A couple of things I've learned about editing in Final Cut that come from taking the online tutorial class from Lynda.com. This is a great way to get up to speed

Icon Based Editing
If you are working with clips that are visual rather than chronological, a good way to go about organizing your initial sequence is to view your clips by a representative poster frame rather than having to rely on the name you gave each clip as you logged and captured. There are two ways to do this.

From the Browser, control or right click in the Name column. Choose View as Medium Icons (also Small or Large) You will get a pallette of thumbnails you can then push around or drag directly into the timeline.

The second way is to choose a column you are not using and control click in the heading. You can then choose Thumbnails, then drag that column close to where you need it to see it.

Custom Sizes
I've been more than stumped with the process of matching SD video to modern screens and wide computer monitors. Eventually I have always had to result to custom proportions to resolve these issues. What I know now is that it is almost always a mistake.

Color Management
I have been adding a color adjustment step on export to correct for the washed-out look of exported quicktimes. I choose the Colorsync filter, choose Generic RGB for the destination profile, and Relative for the conversion method. This is not perfect, but it does get me closer than sending without this conversion.