I also feel like my shop has its ups and downs, which I can't explain since I'm doing everything the same! For example, one day I'll have a lot of views, but very few favorites, and vice versa. The last couple of days, views have really dropped, though I've added new items.
Possible explanations can be that Etsy's traffic varies significantly from day to day. Also, maybe many of your views come from the same viewers? Like, sometimes I'll find a shop I like and click like 30 of their items! I'm sure they wonder why they got 30 extra views but no sales!
It can be frustrating, but sales come when I least expect them.