How do you insure that the new words you create for an alien language are etymologically consistent? French, German and English, or whatever language on earth, are etymologically consistent. Meaning that words sound and look like they're either French, German or English words. When creating a new languages, how do you insure that these new words are "etymologically" consistent, meaning that they're not just random letters stuck together, but they seem to come from a language that really do exist without creating said language.
For example, Akhashanahruhh, doesn't sound like it comes from the same language as Imon.