Finding Hacks

So first I'd like to explain what this thread is NOT in order to clear any misconceptions
This thread is NOT:

• A thread asking how to make hacks
• A thread asking for addies, sigs, or source code
• A thread asking where to learn languages (such as C++, assembly, etc)
• A thread asking about how to reverse programs
• A thread asking how to make hooks

What I am curious about is how game exploits are found in general.
What I mean by this is how to look through references and such in order to locate things such as lifetaker or superbullets, for example, and memory specific things, such as players (as in how to find the array containing all the pointers to the players)

I've had some experience with assembly, to the point that I understand what things are doing (but not quite the level of seeing a bunch of assembly and it being equivalent to having the C++ source), and experience with creating the actual hack, but once again i'm curious as to how these hacks are found (like how did someone find hacks, before sigs and such came out)

If anyone is willing to show me a few things, please PM me with some sort of contact info (such as msn) or post here (but i wouldn't suggest publicly posting info)

TIA