For example: pete, pit, pate, pet pat, pot, boat, put boot, putt, pout, bite, boit?. (isolates the vowels and diphthongs).
pot, cot, tot, dot, *bot, got, sot, *zot, rot, lot, *mot, not, *fot, *vot
pat, cat, tat, *dat, bat, gat, sat, *zat, rat, ?lat, mat, gnat, fat, vat,
Notice we cannot find a complete set of minimal pairs to illustrate each sound, but even non-words like *zot are recognizable: Mott could be a person's name, or a brand name (Mott's Apple Juice) or an acronym (Multilingual Old Trekkers, e.g.) or an onomatopoeic word.
So minimal pair isolation is a TOOL we can use; it is not a principle, it is a shortcut method that can help us find the minimal distinctions of the language; if we made charts and graphs we would discover that the minimal pairs show contrasts in identical environments. We are not looking for the minimal pairs as an end in themselves, but the minimal phonological distinctions, so as to eventually isolate the phonemic contrasts, or phonemic distinctions, and establish the minimal phonemic inventory for the language in question.