Tips & Examples for Academic Video Making in CS and Related Fields?
SciFund ran a class last summer on making academic videos. 

Some tips from that course that I found helpful:


Start with a "hook" to grab viewers' attention, use dramatic tension to keep it. See e.g. this video. (From Week 2 of the course.)
In your script, emulate the way people speak, not write - it will sound much more natural. (See Week 3 of the course.)
When you record your voice-over, use good equipment (you can get a cheap lav mike that works with a smartphone and has pretty decent quality), record in a quiet place, keep your tone level. (From Week 3 of the course.)


All of the class materials are available online:


Week 0
Week 1
Week 2
Week 3
Week 4
Week 5


As for examples of good science videos, Vox has some nice examples of videos that are both appealing and informative. See e.g. this one, or this one. Although theirs are for a general audience, not a specialist audience, a lot of the principles are the same, and I personally find it useful to note things that I think they do well (production-wise) that I can emulate.