It's not just a lack of storage that can make living in a kitchen you can't renovate kind of miserable, it's a lack of usable and accessible storage.
So add those magnetic wall-mounted knife blocks and hanging pot holders.
Whether you're renting and can't do a lot of permanent damage or even if you own a house but just don't have a budget to tear everything out and start from scratch, you can still make impactful changes and additions that will make your kitchen quite a bit nicer to look at (and nicer to use, too).
It seems like such an insignificant element to add to try and create an effect on an entire room, but adding a mirror in the kitchen achieves all sorts of visual positivity.
Just make sure you'll be able to remove whatever product you use without damaging the cabinet material.
(If you rent, just remember to keep track of the changes you make if you'll be responsible for putting things back when you move out.) I once lived in an apartment with these metal cabinets with metal handles that had all been painted over with the same boring paint color, but one day I removed the handles, took the paint off, and had a whole new kitchen look!
(With landlord permission of course.) Never doubt the power of a simple update with new or new-looking hardware.
It's an unexpected element in the kitchen so it instantly makes a statement.
If you have a window, it'll help spread the light around.
You might be tempted to take a jack hammer to whatever awful flooring your kitchen came with, but you can disguise it to save money and not do anything permanent, while still improving the look underfoot.
Use contact paper or vinyl to create designs and patterns on your tired cabinets or make them look like a whole new different solid color with a larger piece of contact paper.