Not involving users in the development process

These may be external users of the application, or end users within your business.

Keep the end users constantly in the picture. Do this by involving them on a day to day basis. Do not do the insane development technique of working for 8 months and then finally introducing the application to the users. They will not like it, whatever it is.

Show them early versions of the software. Let them use it. Let them give you feedback, and above all, let them change their minds without being punished. Look this is about making your company profitable. Trust your end users; they know what works and what does not. Keep them involved and allow them to contribute to the design.