The amount of views you're getting is well reflecting quality of your works - it is very very low. No tags, better description or more models will help you sell more if you won't increase your quality. Judging by your models it's pretty evident that you lack basic understanding about poly modelling. You have just sit down and learn hard to improve your skills, otherwise you can expect only very occasional sells by pure chance. 3D models stock market is very competetive and it's getting even more competetive day by day. It is increasingly hard to have decent sales even with large collection of good models. With models like yours, there's no chance at all.
Try to look at your models from buyers perspective. If you need good model for your project, would you buy this: https://www.cgtrader.com/3d-models/car/sport/viper-sti or this: https://www.cgtrader.com/3d-models/car/sport/concept-coupe
would you buy this: https://www.cgtrader.com/3d-models/electronics/phone/samsung-galaxy-s7-edge-a5f85baf-3643-4562-b0c8-882f38b4bbff or this: https://www.cgtrader.com/3d-models/electronics/phone/samsung-galaxy-s7-edge-all-colors
would you buy this: https://www.cgtrader.com/3d-models/military/gun/dominatornon-lethal-paralyser-from-psycho-pass or this: https://www.cgtrader.com/3d-models/military/gun/sci-fi-gun-03
would you buy this: https://www.cgtrader.com/3d-models/aircraft/other/quadrack or this: https://www.cgtrader.com/3d-models/aircraft/private/dji-phantom3-professional
You have to step your game tenfolds if you want to have at least some success in selling models.