Its really quite simple....
If you don't think abortion is right, don't have one.
If you want there to be less abortions, you can work to ensure that abortion is not the option chosen by making the other options more attractive. That might mean supporting charities and organizations that provide education, housing, and care for pregnant women during pregnancy and long after the child is born. That may mean advocating on behalf of women who choose to give birth. That may mean simply not being a judgmental ass who considers single women or teenage mothers sluts or whores.
If you want to be taken seriously in your opposition to abortion, be intellectually honest. Considering that 92% of all abortions in Canada happen before 12 weeks, before any brain activity, it is dishonest sensationalism to argue against abortion with pictures and posters of late term fetuses. It is lying. Even more so when one considers that abortion after 20 weeks is so rare that it only takes place if the mothers health is in danger. Even Henry Morgantaller won't perform them on demand.
If you want there to be less abortions, you may have to accept that people, including teenagers, have sex even when you tell them not to. You have to accept that abstinence only doesn't work and that proper sex education and access to good birth control will prevent a lot of aborted children from being mistakenly conceived in the first place. Defence in depth, as we call it in IT security. Teach your kids that they shouldn't have sex before marriage if you wish, but also teach them better safe than sorry and get them either on the pill or used to condoms, preferably both.
But you must also accept that you do not own anyone else. You cannot control their bodies. You have as much right to prevent a woman from having an abortion as you do to force a man to donate a kidney against his will - none at all. Part of being free is accepting that people are going to do things you find repugnant and abhor. So long as they don't harm you while doing it. Anything other than this is support for slavery.
It really is just that easy.