INSIST that the guy doing the pointing really does know what he is doing - ask to see other work he has done and don't be put off

INSIST that they put some black dye in the mortar (called "compo" in the trade) so that it blends in - there is nothing uglier than bright white pointing on an old building

INSIST that it is NOT strap pointed but that the mortar is as unobtrusive as possible

INSIST that the mortar does NOT extend onto the brickwork surface

In a disaster scenario you can remove ALL the pointing with dilute hydrochloric acid but the longer you wait the more difficult this will be. If you do it yourself, bear in mind that a splash of acid won't hurt you but soak all your clothes in plain cold water afterwards. If you don't, a week later they will be full of small holes from acid splashes - trust me, they really will be.