I started placing the 3V3 buck converter first. Here’s what it looks like on the schematic:
The LT1765 switches at a high frequency (1.25MHz), which constrains the routing. The datasheet explains that the most important thing is to make the path from pin 3 to pin 2 through D2 and C2 as short as possible. My layout looks like that so far:
Vias to the ground plane aren’t pictured, but the path I was talking about is really short, and I think it will do the trick. The layout and schematics have yet to be reviewed, though.