Simple use:
* The turkey was delicious, especially with the gravy.
* I always have gravy on my mashed potatoes.
More complex uses:
* The gravy was so thick it could stand a spoon. (Describing the texture)
* The chef's secret ingredient in the gravy was a splash of sherry. (Highlighting a detail)
* The gravy was the perfect complement to the roasted vegetables. (Emphasizing the combination)
* Her life was a gravy train, full of wealth and privilege. (Figurative use, meaning a life of ease and comfort)
As part of a phrase:
* Don't get your knickers in a twist - it's just gravy. (Slang, meaning it's a bonus or a small matter)
You can also use "gravy" in a more figurative sense, like "the gravy train" mentioned above. It depends on the context and the meaning you want to convey.