Painting a Concrete brick fireplace

Help! My home was built in 1955 and has a large floor to ceiling fireplace in the den. The brick is concrete(terra cotta in color, no character, vertical ribbed lines on each brick). I am ready to paint it and had originally decided to go solid white, but the look I want is the look you find in "Country Living" - the weathered and worn look where some brick shows thru. Can anyone help me with technique before I begin and mess up? I am afraid if I use a sponge, it will look sponged and I don't want that...I want it to look natural. I know I have to clean the FP with TSP, then prime, but won't I have to use the same technique with the primer? Any help would be so appreciated and if anyone has done this before and has pics, I'd love to see your sesults if you don't mind sharing. Thanks so much for any help! I am excited to get started!!