If you’ve made your gravy too thick a tiny bit of coffee can thin it back out again.
If your sauce is too thick, dilute with broth or water a tablespoon at a time until desired consistency is achieved.
Is your sauce too lumpy? Remove it from the heat immediately and toss it in your food processor to smooth out the lumps and blend the flavours. Add some hot water if necessary, to assist with the removal of the lumps. Then reheat as needed and serve.
Thicken your gravy by adding a tablespoon of instant mashed potatoes. Start there, and add more if needed until it’s the right consistency.
Is the taste of the sauce much too sweet? Add a squeeze of lemon juice. Too salty? Add a drop of milk, cream, or plain yogurt.
Add flavour to your sauce by adding cream, or perhaps various wines and spices, in an effort to liven it up.