Sembra che io fossi un po' pigro fare correzioni all'ultima frase. Per scriverla come la persona di madrelingua inglese la scriverebbe::
"I'll try to make the best coffee you've ever had."
What does a secretary do?.
They say that allwhat a secretary hasve to do is...bring coffee, so I want to tell to my future (I hope) boss: "I'll try to makeing the most goodbest coffee you ever have drunk."