Others are: after s, before or after nasals, before or after voiced or voiceless consonants, before or after r, l, in environment of velars, palatals, dentals, etc. Any regularly occurring pattern can be an environment.
Easiest to start with initial, medial, final. Complementary distribution will quickly be seen, e.g. with aspiration in English consonants.
Another kind of obvious complementary distribution in English: before voiced vs. voiceless consonants, vowels differ in length.
Another: before palatal consonants, vowels may be raised (especially in certain kinds of E. dialects.
Another: after vowels, /r/ is deleted in many dialects (e.g. British, Commonwealth, New York, Boston, southern, etc.)