One of the most used features of ScreenFlow is splitting clips. This allows you to turn one clip into multiple clips so you can remove unwanted video, rearrange it or insert media in between. You can do this by positioning the scrubber on the section you want to split and clicking its lower tab. This will split all clips on the timeline except the ones that are locked. You can also drag the read tab when splitting and it will create a gap by dragging to the right or a transition by dragging to the left. There are other ways to split clips by clicking the letter T or choosing split from the Edit menu.
If you want to split an individual clip, don't use the scrubber. Click on the clip right click on it and use Split Clip. You can also split multiple clips this way by selecting multiple clips. You can trim the beginning or the end of the clip by selecting the clips and clicking trim from to scrubber or and to scrub Then you can drag the clips using the scrubber to the start of the timeline or select the empty spaces by holding Shift and hitting the delete button.