The easiest and fastest way to dramatically change the look of a fireplace is with a premade, full-surround mantel. Both sides and top are included. Home centers carry various styles and sizes, some painted or stained, and others unfinished. Carefully measure what you want to cover and see if this works for you.
You can also consider tiling over old brick for a new look and replacing the mantel with either a premade or custom unit. If you’re able to spend a little more, now would be the time to install a new fireplace insert and glass doors for increased efficiency. If that’s the way you want to go, I would recommend that you hire a professional to do the work for you.
See our video for one pretty example of a custom fireplace makeover.