Wolf if one has no mesora, then one has a severe problem going beyond mixing minhagim. The only ones who wouldn’t have mesora are converts or BTs who’s family has been so far away from yiddishkeit that they can’t recall any customs.
Mixing minhagim isn’t beautiful at all. You can be left with basically nothing. Nisht aheen and nisht ahehr. Maintaining minhag avos is a posuk, al titosh toras imecho. Rav Yitzchok Weiss ztzl even paskined that this means not to change the pronunciation of davening from chasidish to litvish or to sfardit.