All the time, the level would probably be based on the time you have.
You should really document technical specifications for everything. This is then useful for somebody to understand what you have done if you leave or take on the project at a later stage.
Ive also noticed that when writing technical specifications its flags up any issues with your concept idea.
This is just my own opinion.
Good Luck
Jonathan
Jonathan Nachman MBSP, MCTS
Microsoft CRM Technical Blog
CRM Solutions Architect for
Pythagoras