When I do my own shift, I use what I call the rule of laziness. That is, all changes move toward less effort on the part of the speakers. A few examples:

Unless the language is naturally polysyllabic (Polynesian for example) I drop syllables. So Wintersforge may become Winsforge.

If there is a natural consonant or vowel difficulty I may grab it. So Lollytown may become Rorytown, which per dropped syllables becomes Roytown or even Royton.

People have habits of naming. One of the big ones is adding "what is it" to the name. So Pittsburgh City and Newvilletown happen. After which slurring and comfort reduce them all. Los Ciudad de las Angeles...

Applied laziness is my goto tool for this sort of thing.