1. Be a .NET developer, c# developer will be the best.
2. WF4 workflow should be developed and used by developers. Noe-developers? Please leave WF4 away.
3. Use NativeActivity only;
4. Host WF4 workflow in IIS7 as a WCF service;
5. Don't use extension. Use Activity instead;
6. Use WF4 designer provided by Visual Studio 2010, it is not a good idea to build a customized WF4 designer by yourself.
7. Keep it simple! Activity and Activity, only activity.