Having trouble creating user defined model?

Forum,

Thank you in advanced. First let me say that I have been away for a while and I use to be able to do this on a regular basis.
What I am trying to do is build a simple model (10.1) to build a GDB, Create a Mosaic dataset, and add rasters to this dataset. I need it to be flexible and user defined and I can't remember how to add the user defined variables? I want the tool to run starting by

1. Creating the File GDB, user to fill in name and location
2. after the GDB is created (I have a precondition on the GDB for this) Create the Mosaic Dataset
3. While creating the Mosaic Dataset user defines the name, coordinate system, and any other variables desired
4. Then add rasters to the Mosaic Dataset, build pyramids, calculate statistics, build overviews and complete.

Should be easy enough but my mind is drawing a blank, so any input would be greatly appreciated.

Thanks
Steve