Make code hygiene your mantra. Piece at a time, make existing code better and make your code obey all the solid clean code principles you care about. If you wan

Make code hygiene your mantra. Piece at a time, make existing code better and make your code obey all the solid clean code principles you care about. If you want to TDD, make artificial seems on everything new and do TDD on the new stuff and start putting tests around areas at the smallest levels you can and start refactoring slowly in areas that you are touching. Make it a process that you always follow to have good hygiene. You'll eventually end up with clean code.