The mixture for re-pointing should have a lot of sand, some lime and a little cement. The recommended mortar mix for pointing is 9: 2: 1: that is 9 parts of coarse or sharp sand, 2 parts builders lime, 1 part cement. A slightly stronger mix is 1 part cement, 1 part lime, 6 parts coarse or sharp sand.
The pointing should be slightly recessed. Never have projecting pointing, as this will cause damp. If there is a damp problem don’t just assume that all your pointing needs replacing damp can have many causes such as leaking guttering, blocked airbricks or blocked chimneys.