While attempting to write an all-encompassing manual for the TAS Editor toolset, I wrote the textbook on TASing.
http://www.fceux.com/web/help/taseditor/
Given the size of the book, it's probably not an easy read, but I highly recommend everyone to take a good look at it, because it's the only paper of this kind. Before, there were lots of talk about specific playing tricks like Luck Manipulation, fighting bosses and finding glitches, but for some reason no one spoke about intricacies of actual process of making the Input for a TAS movie. And it's much more than just "playing with savestates". In my opinion, this misconception is what rises the bar so high that newcomers cannot compete with old TASers and have to find an obscure game that would make a publish-worthy TAS and thus motivate them to learn TASing the hard way. Now, instead of learning TASing by trial-and-error I suggest all newcomers to read the Beginner's Guide section:
http://www.fceux.com/web/help/taseditor/BeginnersGuide.html
Beside TAS Editor specifics, it covers the following topics:
* the difference between using savestates for playing and for TASing
* working with segments
* optimizing by repeatedly redoing
* finding factors by trying different approaches
* finding factors by rewatching and changing scope
* quick resyncing of Input
* using 10 savestate slots efficiently
* comparing alternative strategies of playing through large segments
* fastest way to find the first possible frame for a buttonpress
* general luck manipulation
* basics of Lua scripting
* using the new tools (Markers, selection counter, green arrow, ...)
Since the Guide is a part of TAS Editor's documentation, it's naturally leaning towards TASing in a highly-visualized environment like TAS Editor (FCEUX 2.2.0) or future TAStudio (BizHawk). Because that kind of working environment is simply more user-friendly than plain old savestates and Frame Advance. But anyway, there's also fair share of describing the traditional TASing method:
In this thread you can ask questions and post opinions about the book. Later I also plan to add some videos, but for now just some nice image from this
submission: