A preamble: I\'ve been using PHP for over 8 year every now and then, but never used a framework, only wrote scripts and addons. Mostly I used code generators like CodeCharge Stu
If you're already acquainted with MVC and design patterns, then why not look into tools to helps you code faster?
Although I generally like free tools, I must say using Zend Studio IDE (based on Eclipse) helps going faster (30-day free trial).
The main points (apart from the debugger/profiler):
and -last but not least-
Just make sure to have a computer with a whole lot of memory!