Blackheads are caused by partially blocked pores. The "black" appearance of them is not caused by dirt, but by the oxidising effect of air on the sebum (oil) in a blocked pore and the melanin pigment from the dead skin cells.
The best way to get rid of blackheads is to remove the cause of them � excessive sebum (oil) and dead skin cells. Use only products made with natural ingredients that are not too astringent. Harsh products can strip the skin of oil, causing it to produce more sebum which leads to more blocked pores. Don't be afraid of using cleansing products containing natural oils, such as jojoba or coconut oil to cleanse the skin. These oils are close to our natural oils, so they don't block the pores. Use a gentle exfoliator every day to remove dead skin cells so they don't block pores. Just remember to be very gentle, over exfoliation can exacerbate the problem. Avoid products containing the following: alcohol, isopropyl mystate, lanolin, sodium lauryl sulphate, sodium laureth sulphate, propylene glycol, mineral oil and parabens.
Do not to try and extract them forcibly, either using your fingers, fingernails or a comedone (blackhead) remover. This can cause permanent damage to the pores and stop them working properly for ever. You may squeeze some of the blackhead out, but you could also force some of it even deeper into the skin, which may lead to infection (large spots, pimples or even cysts) or permanent damage. Touching your skin should generally be avoided to prevent cross infection.