Everybody knows that bitcoin blenders anonymize your coins but shouldn't you follow some precautions for your mixing to be effective? I suppose that mixer is fair (it won't steal your money and does not trace anything) but if it simply takes n amounts from various users, and sends them to n destination addresses then operation is meaningless. What should proper mixer fulfill for obfuscation and how it must be used properly?
This guideline says that I have to submit my coins to mixer in parts
if you want avoid potential metadata analysis correlation then you should break up your transactions into smaller, randomly determined amounts.
Is it the only thing that I must care about? What is the point of that? If investigators can trace individual amount then how can splitting your amount into subamounts obfuscate anything? Does it mean that you should prevent re-uniting of the amounts?