read up on using the ripple tool.
it will (almost) change your life!
basically you select the ripple tool (from the tool palette or hit “r” twice)
select the side of the edit you want to affect,
then either drag, or enter a specific value.
+12 will ad 12 frames
another approach is to simply select the edit point (hit “v”)
this selects BOTH sides of the edit, but hitting the ‘U’ key wi toggle which side is selected,
then type in your value
OR… (lots of ways in FCP!)
double click on the edit. this will open the TRIM WINDOW
use JKL keys to play (not space bar)
lay forward a bit, mark a new out point,
NOW use spacebar to preview the change.
still images night not be the best use for trim window, but t’s a great tool when you need it.
good for looping the edit, and adding or subtracting frames till the edit point is just right
nick