Anyone develop software solutions on the side or fulltime?

N2IT

From a consultanting standpoint I was wondering how you charge for a piece of software developed.I recently began developing a piece of software, Access 2010 database that is fairly detailed. Several queries and reports. 3 Forms and 5 normalized tables. It's a work effort tracking database. It's pretty slick, I have combo boxes and constraints on all critical fields. I tested the tables it's good to go, but I have a few more tweaks before I start to UAT.

Do you all normally charge by the hour or just got for a flat rate? I started building this about a week ago and should of negotiated upfront. Would a flat fee be out of the question or is it based more of man hours and work effort? Generally speaking.