Stackoverflow users, How do you keep yourself from creating large classes with large bodied methods. When deadlines are tight, you end up trying to hack things together and it ends up being a mess which would need to be refactored.

For me, the one way was to start with test driven development and that lends itself to good class design as well as the SRP (Single Responsibility Principle).

I also see developers just double clicking on controls and typing out line after line in the event method that gets fired.

What are your suggestions?