I work in a fairly relaxed development environment. I guess you could call it RAD. Most Web development work is Rapid Application Development by nature anyway. That said, I'm not totally ignorant of the newer methodologies such as Test Driven Development (TDD). However, all the tools and methodologies in existence will not make the slightest bit of difference if your mindset and approach are out of whack for the job at hand.
10 Rules for Debugging - Irish Style
1) Keep it simple, stupid (KISS principle). Many people get in a bind because when given a choice between a simple solution and one that seems more elegant, they of course go for the latter. Elegant code is achieved through experience and refactoring. Get it working first!
2) Divide and conquer. Why look for a needle in two haystacks? Narrow it down.
3) Don't let your emotions get the better of your thinking - always a recipe for disaster.
4) Never panic. Only wimps panic. In the face of insurmountable odds, get drunk, read Hemingway and proclaim your genius loudly to all.
5) Your brain works productively for 40 minutes at a time. This is a universal rule and you are not different. At the 40 minute bell, go away from your desk for 10 minutes as you're only going downhill from that point on. For some strange reason, most people cannot accept this fact. Look around you at work to see who the idiots are. "Gee, I'm sure to get promoted if I never leave my desk"... and pigs will fly.
6) Do not presume that the first change you make to your code that makes it run, is the actual solution. You may have been looking at a symptom...
7) There's a reason why error messages are neither friendly nor helpful. If the guys who penned them were shining beacons of descriptive prose, they would be working for the New Yorker instead of doing that job in the first place. Guess how they get their kicks? Never rely on your bog-standard error message clueing you in to anything other than the onset of an early ulcer.
8) Learn how to think, if you haven't already. I was in my 30's before I started asking the right questions about anything, let alone software development. Ask someone what they really want in life and 90% of the lemmings will reply that "they want to be happy". See where I'm going with this?
9) Creativity is your number one asset. Be creative and learn how to develop new synaptic pathways in that grey matter. The brain needs to be exercised in different ways, regularly. Get out of bed on a different side tomorrow and put your clothes on in a different order. If you really want a laugh, do everything in the washroom with the opposite hand to the one you normally use.
10) As for ASP.NET, if you don't know the life cycle inside-out, you shouldn't be wasting your time skipping a chapter to debugging in the first place ;-)