Ideas that actually change the room
The best tiling fireplace ideas do one of three things. They go big, running the tile floor to ceiling to draw your eye up and make the wall feel taller. They go textured, using a 3D or stacked tile that catches the firelight and throws a bit of shadow. Or they go classic, a marble or a warm stone that looked good forty years ago and will look good in forty more.
The thread running through all three is contrast. The fireplace should read as the thing the room is built around, not disappear into the same paint as the walls. A dark floor-to-ceiling surround makes a modern room feel deliberate. A bright white stacked tile keeps a smaller room light. Pick a direction and commit, because a fireplace that is trying to blend in is a fireplace doing the one job it was not built for.
Tiling a fireplace surround without it looking like a box
The surround is the tile framing the firebox, the opening the fire actually sits in, and the usual trap is treating it like a plain rectangle. The fix is layout, not fancier tile. Run the tile floor to ceiling instead of stopping at the mantel and the whole wall grows. Turn subway tile upright, or set it in a herringbone weave, a diagonal zigzag, and a cheap tile suddenly looks like a design choice.
The move that separates a clean job from a busy one is centering. We plan the pattern so it lands centered on the firebox, with the cut tiles falling evenly on both sides, the way your eye quietly wants them to. Nobody walks in and says the layout is centered. They just feel that the wall looks right, and they cannot tell you why. That is the point.
How tile behaves near heat, and why the material matters
A fireplace gets warm, so the tile has to not care. Porcelain is the easy answer, because it absorbs 0.5% water or less (ANSI A137.1) and takes heat without sulking. Natural stone like marble, slate and travertine handles heat too, and brings a depth that porcelain imitates but never quite matches. What I steer people away from near a working firebox is anything that is really a plastic pretending to be tile.
One thing I do not touch: the clearances. A working firebox has required gaps to anything that can burn, set by the appliance maker and the building code, and I tile to those numbers, I do not invent them. We are the finish, not the firebox. (Staying in my lane is how everyone stays warm and nobody's insurance gets interesting.)
Tiling over a brick fireplace: yes, but flatten it first
You can absolutely tile over a brick fireplace, and it saves ripping the old one out to start over. Here is the catch, and my one strong opinion on the whole subject: a wavy fireplace tile job is almost never the tile, it is a lumpy wall nobody flattened first. Brick is basically a very confident suggestion of a flat wall.
ANSI A108.5 wants at least 80% of each tile's back stuck to the wall, and you simply cannot hit that over bumpy mortar joints. So before a single tile goes up, we flatten the brick, either skimming it level or hanging a backer board, a flat cement panel, over it. Flatten it and the tile lays out crisp and lasts. Skip it and you get hollow tiles sitting next to heat, which is exactly how they crack and pop off a couple of winters later.
When tiling the fireplace is not the move
Now the honest part, the bit other contractors skip: when I would tell you to wait. If the firebox itself is cracked, or the damper and flue need work, that is a chimney and hearth job and it comes first. I will happily tile the wall once the working parts are sound, but I am the finish, not the fix for what goes on inside the fire.
And if the brick you already have is genuinely flat and you love it, do not let anyone talk you into covering good brick just to be doing something. If you are set on a full tiling fireplace wall, corner to corner and floor to ceiling, just know a big tiled wall shows every flaw the old brick was politely hiding, so the flattening matters even more. I would rather tell you that now than after the grout lines start to wander.