The most common kitchen lighting mistake is relying on a single bright source of light from above. This creates high contrast and glare, as well as uneven light around the kitchen. It also causes your head and body to cast a shadow over the area where you're working, making routine prep tasks harder to see. Dissolve those harsh shadows by setting your lights to overlap one another. If you've got recessed cans, position them within 2 or 3 feet of one another so their beams overlap. If you like the look of a central fixture, choose one that shines upward to bounce light off the ceiling for a more diffuse glow. Having multiple light sources and directions will eliminate this spotlight effect.
Ambient lighting bathes the kitchen with enough light to see, but the detailed and focused work of chopping, mixing and reading recipes requires more concentrated light. Position lights that point downward directly above counter areas to illuminate these workspaces. Referred to as task lighting, these fixtures should be on a separate, dimmable switch for added control and positioned so they won't cast a shadow when you're working at the counter. If you're existing ceiling can't accommodate recessed lighting (or it's not the right fit for your house), you can get the same effect from under-cabinet lights, surface-mounted tracks or hanging pendant fixtures.