I've never vlogged or even uploaded a video to YT... But I am a YT junkie. With that said, here is my honest advice:
The single most annoying thing about most vlogs is the annoying long intros on every f'ing video. The longer, the more annoying ~ The shorter, the less annoying. So please avoid the temptation to show off your newly learned editing skills with what you think is awesome footage & music. No one wants to sit through the proverbial "in a gadda da vida" drum solo every time they watch your f'ing vlog. What you think is an awesome intro only serves as a time-vampire for everyone else who might want to actually hear what you have to say.
If I had a vlog (not gonna happen) and wanted an intro, the intros would be no longer than 5 seconds - Use some sort of recognizable logo/icon/avatar - Maybe some background footage or animation - Maybe some music/sound fx. Keep it short short and sweet so that the meat of the vlog stands out.
On another note: Feel free to make your outro as long as you like if you wish to provide onscreen info, or if you still feel the need to show off your newly learned editing skills. That way your viewers can either watch it or just stop the video to get on with their lives.
P.S. I discovered that some folks are very personally attached to their intros, kinda like a security blanket. I have seen them throw a temper tantrun and even ban me from their YT channel for even the slightest mention that their intro is painfully long and only serves to take away from the actual vlog. Don't be that guy.
