Light colors and lots of light. I have a windowless kitchen and have 2 ceiling fans (5 lights each), under the counter task lights, and a huge over the sink flourescent light that is hidden by the valance. I painted my ceiling with a glossy paint, it's pressed tin, and the light bounces off it. Go light with flooring and countertops if you have those options.
A great trick I’ve used in the past is to get a picture of a sunny day and hang it over my sink. Then I put a simple bright curtain up framing the image. If you are good with electrical you can install a light over the sink to simulate daylight coming in.
I have windows in my kitchen and purchased a string of those small LED lights running them under the cupboards and over my kitchen window. Sure looks pretty. Hanging scenic prints will add a nice touch as well. You can even purchase canvas prints that have lights in them.
If you have space, mount a small mirror to bounce any artificial light. Using chrome or brushed nickel faucets, stainless appliances or bright white appliances will make the area appear larger. Consider a mirrored backsplash, under glass, over the stove area.
Use light colored curtains and, if possible, glass fronted cabinets to also bounce interior lights. Use multiple LED lights on dimmers, rated for 3000-3400 Kelvin to really brighten the space.
If your flooring is lighter, it will make the kitchen space appear brighter, as well.