First thing - People got to prepare their mindsets first. They've got to understand and realize that having children is not about them anymore, it is all about their children now. So you've got to be matured enough to throw away childish and selfish things in your being.
Secondly - People must be prepared financially. Being a parent or having kids or children is such a huge responsibility. You've got to be financially stable in order for you to provide for your children and in order for them to grow up appropriately. Having their needs met makes them grow properly. Mentally, physically, emotionally and financially.