title_body: Designing a mildly weird phonology
upvoted_answer: Probably the best technique is making the language weird by absence. Instead of giving the language weird phonemes, make it lack the most common phonemes. A language with 5 vowels but no /a/, /i/ or /u/. A language with several consonants, but no /p/, /t/, or /k/. Or totally without bilabials. Or with no stops.