How to actually improve CTR?

so I make let'splay style videos edited down to about 50% of original length and my viewer retention is actually going off the charts. this post was mostly motivated by me looking into my 40 view video and realizing it has 20 hours of watchtime... like I know that's really freaking good. and then it has 0.9% ctr, so it's still struggling

what kinda thumbnail style do you guys use for that style of videos and what do you say in the title?