VIN and GND traces should be as wide as possible to reduce trace impedance. The wide areas are also of advantage from the view point of heat dissipation.
The input capacitor and output capacitor should be placed as close to the device as possible to minimize trace impedance.
Provide sufficient vias for the input capacitor and output capacitor.
Keep the SW trace as physically short and wide as practical to minimize radiated emissions.
Do not allow switching current to flow under the device.
A separate VOUT path should be connected to the upper feedback resistor.
Make a Kelvin connection to the GND pin for the feedback path.
Voltage feedback loop should be placed away from the high-voltage switching trace, and preferably has ground shield.
The trace of the VFB node should be as small as possible to avoid noise coupling.
The GND trace between the output capacitor and the GND pin should be as wide as possible to minimize its trace impedance.