Recommendations to improve sales

I have noticed a few people mentioning that sales are down at the moment, however, i am wondering what i could do to improve the chances of selling items. Ironically, i have found that becomming a powerseller and opening a store has slowed down sales ... I was under the impression this would boost them. Anyway, my listings all have very detailed descriptions, they have high quality photos and the prices are very competitive. Most are getting the views and many have watchers they just are not getting the sales. Not really sure what else i can do to lock down more frequent sales. Any suggestions would be very much appreciated.