One of the best methods entering day-to-day patient data in a GP's practice is the Problem Oriented Documentation, in English also called Problem Oriented Medical Record (POMR). The Free Dictionary describes it like:

  an approach to patient care record keeping that focuses on the patient's
  specific health problems requiring immediate attention, and the
  structuring of a cooperative health care plan designed to cope with
  the identified problems. In contrast to the traditional “diary” method
  of record keeping organized according to the source of information
  (such as a physician or nurse), the POMR uses progress sheets that
  integrate all written notes under labelled problems.

While there are (or were) software products that use this kind of approach (Gnumed, PRODOK, FreeMedForms partly), they all don't find a way to properly assist the doctor in his way entering data, but urges him to fill the database with data that should be in the format the database schema was designed for. I never saw a well-designed human user interface that helps you with your data problems - you additionally had to solve the computer's wishes, how data should be saved.

Some links I found across the Internet.

• Fülleborn, Meffert, Heisel: Problem-Oriented Documentation of Design Patterns , Düsseldorf, 2009
• Definition of “Problemorientierte Dokumentation” (German) at Wikipedia