Here is my experience with these:
Clickbait title : Bad, unless it just seems Clickbaity but then ends up being accurate then this is quite funny. If you want an example I can try and find one.
Open mouth facial expression: ???
(Literally) Sexy content: Sure, haha. But you won't find that on my channel. ITSKATKAM is a soft example of this.
Countdowns: If you mean lists. Cyclecruza and Yammi Noob do this and they have a lot of success but I think this strategy works better for established YouTubers.
Rankings: Same as above and have had success.
Upload scheduling: Yes! I do this. I think this helps with YouTube ranking and the actual video quality of your videos since it gives YouTube more time to process your video before you release it.
Frequency of uploads: Yes, staying relevant is always good. I upload once to twice a week.
Sticking with a narrow theme/ subject: VidIQ thinks this works. They call it Nicheing down.
I find doing reviews, unboxings and making content people are looking for helps with views. It is not always fun to make but if you are looking for views and subs this may be a good strategy.
I personally like riding around on my motorcycle, passing traffic and recording that. : D