Some of our Favorite ones to try
Transitions between clips give the movie more visual interest.
In the Effects And Transitions view of the Media panel, collapse the Video Effects group.
Open the Video Transitions group, and then expand the Dissolve group. To animate the thumbnail of a transition, click it.

Drag the Additive Dissolve transition in the Sceneline, and place it between the third and fourth images
In the Monitor panel, click the Play button to see the transition.
In the Properties panel, you can adjust durations, start points, and end points for transitions. Select Show Actual Sources to see a preview of the adjacent clips.