OK, some ideas. Take them or leave them, but I think they are all important to consider:
-skip the default bright blue intro title screens
-skip the fancy transitions - stick to straight cuts, and perhaps short cross-fades and fades to black or white
-use slow motion sparingly
-see if you can pick a song that isn't associated strongly with something else yet
-always finish your tricks cleanly
-spend as little time as possible accelerating the diabolo on camera
-try and avoid repetition - better to have a great short video than a long repetitious one
-vary your backgrounds and your shooting angles
-if you really want to make it stand out, time your diaboloing and video cuts to the music (best yet, know what music you're going to use before you film it)
-try and avoid 2 minutes of black video at the end

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Read Martijn's excellent post on audiovisual design!!!And finally:
what I can do better to get a nicer video thats very enjoyable to watch if its just gonna be Trick - > new clip -> Trick.
Don't make it just a video that goes from trick to trick to trick! Perhaps you want to tie it together with a theme? Perhaps you can set the mood or tell a story through some other clips (setting up, walking somewhere, the scenery...). Watch some of the videos you consider "good" videos and you'll get some ideas. (
Looking for ideas?) Are you a guy putting on his headphones, tuning out the world, blasting some music, and jamming around the city (The Tune)? Are you 2 guys tearing up playgrounds while being haunted by a bright yellow beach ball with a smiley face that hides in strange places everywhere you go (Smile)? Are you 2 shoe obsessed dudes in the 'hood rocking out sick tricks in cool places (The 5th Element)? The list goes on and on...
Think about it, plan it, and then do it!