Those of us with Afro hair, because our hair is so curly we are prone to ingrowing hairs. After shaving the hair root remains in the follicle, most will grow out without problem and in a few days need shaving again. Unfortunately some curve round and become ingrown causing a lumpy reaction. The problem can be made worse the next time you shave if you nick the bump making the inflammation worse and risking infection.
Shaving dumps are caused when the hair as it grows curls back and starts irritating the skin, burrows into a pore where it continues to grow causing a lump.
If an ingrown hair has occurred there are few, if any, products which can deal with the hair, despite the hype. Once an ingrown hair has occurred the best solution is to soften the skin by putting a warm wet towel over it, then using sterilized tweezers ease the hair out of the bump. Resist the temptation to pluck the hair out completely as the follicle could heal over and cause the same problem when a new hair grows.
Shave in the direction of the hair growth, your shave won't be as close but it's less likely for whiskers to retreat below your skin.
Don't stretch the skin while shaving, this can make the whisker retract into the skin and unable to grow clear of the follicle.
Avoid an ultra smooth shave, if the hair is above the skin it can not turn into the follicle.
Keep your skin clean, particularly before shaving, this will stop dead skin cells, grime etc, blocking the hairs growth.
Use a toothbrush to brush the hair and straighten it before it starts to turn and become a shaving bump
Permanent hair removal, a little extreme, but you can permanently remove hairs in the problem areas through electrolysis or laser hair removal if other options have failed.