1. Playing with time
It's frustrating when you've laid down an arrangement, only to find you could do with adding an extra few bars right in the middle of the song. Well, you can! First, to select a portion of time, hold Ctrl then click and drag on the timeline (at the top of the Playlist). The point from where you click is where the new section will start, and the length of your drag determines the amount of time you'll add. Let go of the mouse button but keep Ctrl held down, then click Insert. Your desired amount of time will be inserted, with the clips shifted to the right. If you want to do the same, but slice and move all clips, repeat the process but hold Ctrl+Alt, rather than just Ctrl.
(Continue reading at: http://www.musicradar.com/tuition/tech/7-fl-studio-power-tips-p32-646965)