Transitions and effects used in moderation can really make your video pop! These elements can take an otherwise boring and flat video to the next level. But don't go overboard, too much of either of these things can make your video look cheesy. And there's enough of those videos on other sites ;)
Transitions can help the flow between clips. You can add fades, wipes and other animated movements to help bridge the gap between tow videos you are editing together. Transitions are added by choosing 'Animations' in the top menu bar and then clicking the white space between two clips and then clicking on your transition of choice. Place your mouse over each transition thumbnail to preview it before your commit. Again, play around with a few transitions that you like, but a standard one we recommend is the 'Cross Fade'.
Effects can greatly alter the look and feel of your video. You can add effects by selecting the clip of your choice, choosing 'Visual effects' and then clicking on the effect you want. Just like transitions, placing your mouse over each effect thumbnail will give you a preview of what your clip will look like. Don't add any effects if it's unnecessary, only if you feel it adds something great to your video.
Transitions help the flow between clips
A simple fade in and out will usually look great
You don't always need transition between every clip
Place your mouse over transitions and effects to preview them
Don't add effects just because you can, only add them if appropriate Continue to the next step, Adding Text and Titles