What is the best way to paint my brick fireplace.

white wash

Thin latex paint to a stain consistency and dab on the brick. Personally, I don't like the mortar colored the same as the brick, but it's your choice. Good luck.

I've used a stippling technique. My dad cut a cellulose sponge (not the soft fluffy kind) the size of the brick and then glued it on a thick (so I had a place to hold to when pressing) block of wood the same size. We first painted the bricks the under color my mom wanted and then used latex paint the color she wanted on top. I thinned the paint with some water in the roller pan and then the technique was to dab the sponge block in the paint and drag the excess off has you pull it toward the edge of the paint tray. The sponge shouldn't be too wet. Press firmly just one time and keep going until the paint is a little faint and then reload the sponge. Mix up the starting point after that so the first, darkest brick isn't in a pattern but scattered randomly across the bricks. My dad painted the bricks including the grout with white paint so the white showed but the bricks were stippled with taupe color paint. The original bricks were a sickly yellowish. Of all the home improvement projects that they were doing on their house, the fireplace was the only one we didn't have to do over! I wish I had a picture to show, it would probably make it easier to understand.

I should have told you, we practiced a few times to make sure this was what we wanted to do.

please don't paint your brickwork!!!!