A floor lamp nestled against a window is a smart substitute for daylight so that when the sun goes down an ambient glow will pour in from a similar direction to balance the central light overhead.
If your cabinets don't go to the ceiling consider adding lights above the cabinets. Using a more powerful light source such as a T5 fluorescent increases the reflectivity of the ceiling thereby increasing the light in the room. While increasing light levels is important it is equally important to minimize glare. Use matte finishes to reduce light flares and glare.
Bright idea for dimmed lighting: To make the most of your lighting install the highest-wattage lightbulb possible then dim it down to accommodate the mood and lighting needs. Consider putting dimmers on both overhead lighting and lamp lighting.