Having a consistent process for how assignments are posted and work is turned in.  

A discussion board should have the same framework as a discussion in class.  I use the "no hogs, no logs" for in class discussions to make sure there is a balance of opinion in the discussion.

Students need to prepare themselves for online classes and make sure they have the time management skills and self motivation to complete the course.

Proper conduct needs to be followed and enforced in all communication types.

In whatever communication tool is used the appropiate student teacher relationship should be followed.

Teachers need to understand that they cannot just post assignments to teach an online course but evaluate what they do to make it more effective.

Learning how to motivate students in an online world is vastly different than the classroom and is important for student success.

I have only used asynchronous but there is value behind synchronous learning as well.

Developing an online teaching style is important to improve the comfort of the teacher.

Student evaluation should also be used to compare how various learning objectives were taught to find out what students found to be the best way.