You are living in the modern world, not ancient Rome. If you would not use a word when speaking with a colleague in the hall, it is probably legalese. Therefore, resist any Latin word or phrase that can be written in modern English. And if you do use Latin or other legalese when you speak, your problems are far beyond anything that I can help you with.
Many commonly used phrases, such as “i.e.” and “e.g,” are Latin—and legalese. “E.g.” stands for “exempli gratia” and simply means “for example.” “I.e.” stands for “id est” and means “that is” or “in other words.” So why not just say “for example” or “that is?” But do use “e.g.,” rather than “for example,” in introductory signals that cite to cases, such as “See, e.g., Smith v. Jones.” (The Usage and Punctuation Guide in my book suggests alternatives to common legalese.)
And foreign phrases that are terms of art, such as “res ipsa loquitur,” “habeas corpus” or “res judicata,” are permissible . These phrases are considered common usage in legal writing, so they do not need to be italicized.