If you have a some extra cash in your budget, here some modern toddler beds that I'm loving. They are simple and reflect a minimalistic aesthetic. With beds like these, you have a blank canvas that will allow you to add bedding with lots of colors, patterns and designs.
My favorite option is Spot on Square's Hiya bed, it's been our number one pick for toddler beds since our search began. We purchased Jack's crib from Spot on Square so I can vouch for the quality and design of this company.
Spot On Square - Hiya Toddler Bed -$449
Argington Petra Toddler Bed - $358
Oeuf Toddler Bed Classic -$620