Rion Williams shared his ideas on Asp.Net forum related to Custom CMS Application in Asp.Net as:
Common modules include :
- Responsive Design - one of the core themes is fully responsive for both desktop and mobile interfaces
- Commerce Modules - several are available and you can find a tutorial on building a fully-functional eCommerce site in Orchard here.
- Theming and Ease of Design - since the CMS uses the Razor View Engine, you can easily add nearly any design / layout that you desire.
Consider trying out each of the above suggestions to see which ones that you prefer and suits your needs the best as with most things there is never a single "perfect" solution.