I am so glad you are asking this! Most people skimp on thinking about this and that's what ends up hurting them when it comes to renting them out. That's why as a realtor, I also became an interior designer because now-a-days a place has to look good to rent. We are such a visual society and there is no going back on that. So thank you for not just going to home depot and buying whatever is on sale and putting it in. That always makes it so much harder to rent, or secure a great tenant.
Here's my standard go to list now for long term rental updates:
-LVP that looks like wide plank white oak
-Ultra Pure white on all the walls
-Vertical/ modern stack backsplashes and showers
-Pop of color on the cabinets (pop of color can include black too)
-Butcher block countertops (lower end) or white quartz countertops (higher end)
-Modern light fixtures in brushed brass
Keep it neutral still but a couple of style choices with the light fixtures (which are cheap) and it will appeal to the masses.
Good luck! You got this!