depends on what style you have selected,

and what style you've chosen for the look of the space.

Contrasting, statement? something less dramatic? too many variables.

It really IS a personal choice, I'd suggest something like this, you either like it or you don't.

Sometimes, it's easier to eliminate ideas than choose... it's a start.

My cabinets are slim shakers in the color Greek Villa SW. My island is Iron Ore SW. The countertop is Calacatta Brazil quartzite - a lighter quartzite. We will be running it up the backsplash as well. Our island will also be a waterfall island. We’ve selected a satin brass faucet and plan to do the same for cabinet hardware. I would say more of a transitional style.

That's tough - such a personal preference. I happen to prefer pulls on drawers - single pull, wider if large drawer. I don't mind knobs on upper doors. Don't like them on lower - I am at the right height to get my pants pockets caught some times.

Here's some pics for inspiration:

I prefer pulls on drawers and knobs on cabinet doors, but I did use some pulls on doors for my mudroom, laundry and hallway built-ins. So it depends on the design, use and look that you prefer for a particular location.

Lots of photos on Houzz to give you ideas. Search bar at top. Type in "kitchens" and then select "kitchens IN PHOTOS". You will see thousands of photos!

As an aside, a waterfall countertop is not consistent with transitional style. You might consider saving money by not doing that. You're already doing your backsplash in the quartz, so you will have plenty of it in the room. As for knobs and pulls, I am with everyone else who has already commented. It's very individual. But here's another vote for knobs on doors and pulls on drawers.

I tend to like knobs on upper cabinet doors and pulls on drawers.

Thank you all! My only fear is that the knobs will look too small on the cabinet towers. Should I add pulls on those and knobs on the other upper cabinets or will that not look right?

if the knobs are strong enough to open the cabinet that's all you need.

the cabinets are the statement, not the hardware.

It all depends on how prominent you want them. If you look at the picture above, there are a few tall doors with just the knobs.