There’s one other way to avoid appositives that I forgot to mention.
You can make the noun and its description the subjects of two consecutive sentences, like so:
The former chairman of the Joint Chiefs of Staff says he’s now enjoying his retirement.
John Shalikashvili left the top spot at the Pentagon in 1997…
This works because English is highly asyndetic. That means the sentence structure carries much of the meaning, and so fluent speakers of the language understand how words, phrases and sentences relate to each other without the help of a lot of conjunctions and connective words. Thus it’s clear the subject of the second sentence, John Shalikashvili, is the same person as the subject of the first sentence, the Joint Chiefs chairman. (And incidentally, that previous sentence works just as well without the word ‘Thus,’ which is my point.)
Moreover, we’ll come back to ‘asyndetic’ when we talk about why you can completely do without ‘moreover.’
UPDATE: I am informed by a few authorities (i.e. broadcast writing books) I’ve consulted that this consecutive-sentences trick is a print construction and therefore bad. Listeners would assume the “Joint Chiefs chairman and Shalikashvili are two different people. Let’s just say I disagree, but concede there are some circumstances where the writer’s intention might be ambiguous (which is bad). You should be aware of that as you write, and use your judgment.