New hardware and drawer pulls would add some detail, could use different styles as well. On your lowers do solid colors and on the uppers use same size as your lowers but do a clear handle with gold/brass accents.

Oh I like that

I’d redo the hardware. And new lighting. After you get the new countertops add some sort of backsplash maybe.
( the new countertops you get:
Leave out that 4” lip. You don’t need or want that...)

I’d also maybe add a runner on the floor.

Paint walls and area above short backsplash a deep brown (to complement countertop & floor).

Lighting could really help this sweet kitchen. Maybe replace the florescent light fixture and the pendant above the sink. New softer looking hardware. Rug and some dish towels in a color you like.

Some simple ideas.

Lunar Pendant Form No. 601, Blue Glass Shade, Brushed Nickel Hardware, 4w Led · More Info

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Modern Persian Boho Vintage Medallion Area Rug, 5 X 8 · More Info

Maybe lights like these below

North Point · More Info

I think painting the walls of your kitchen a cool gray or blue or a color you love.

2018 Christmas Home - Easton Village - Lake Elmo, MN · More Info

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Waypoint Living Spaces Gallery · More Info

Cosmas 9444-128SN Satin Nickel Contemporary Cabinet Pull · More Info

"...and we plan on making the counters white/grey marble-looking..."

What does that mean please?