The whole problem is in getting the grasp of low-level thinking. There's not much use in trying to write a tutorial specifically for TI-basic programmers, in my opinion. (no offence intended) It would be better to teach, as Galandros said, right from the ground. Basically, if you can do bit math and you have a reasonable idea of how a computing system works, you should have little trouble learning those low-level languages, provided 4 things: good attention span
, time for learning, time for coding, and time for headaches...
DJ is right though: some people indeed are better at designing than at coding.
And, as ztrumpet said, even if you never get far in asm, you did learn some about the basic structure of a computing system, which is of great help while learning new languages like C or C++. (speaking from experience here; I just didn't have the time, nor the motivation to get far into C. I do want to get fluent in it before I go to university, however...)
(on a semi-related note: I'm sure there are people in the BASIC world right now who are far more intelligent than I, but are kinda 'frightened' by the look of the language
)