Be relentless when decluttering your kitchen. Stow or get rid of any unnecessary items.
Clear the countertops. Leave no more than two appliances in view. This will give the impression that there's a lot of counter space available.
Make sure the sink shines. If regular cleaners don't work, there are a number of specialty products available for cleaning sinks of all kinds, including stainless steel.
Consider making upgrades. You could do something as simple as replacing cabinetry hardware, or go as far as installing a new countertop.
Paint or stain cabinetry. One of the most affordable and impactful improvements you can make to the kitchen is painting. A new coat of paint or other finish can make older, worn cabinets look like new.
Add some fresh flowers in a vase. Flowers brighten up any room, expeically the kitchen.