i come from a cash game background, but used to play more MTTs. and, LAGgy players like to push small edges...the good ones. the bad ones just like to push. you have to discern the two by watching and note taking.

look for patterns. does he bet small when he hits the flop? how does he play in bigger pots? does he 3bet with crap, or solid holdings? things like that.

but, in general, i take my chances with TPTK against them by raising the flop, if they dont drop, i fire again on turn, if checked to. but, thats all so general, it is probably barely even helpful.

as for "reading the donkeys." i would say that standard abc poker is profitable enough. i wouldnt try until i graduate past the complete fish fests. i would, 90% of the time, just play my cards against a likely range and the board. you will beat them more times than not.

you cannot make moves on the unpredictable, donkey players. dont try.