I used the following section from Chris Schwarz Six Board Chest Chapter to help me install the moulding around the chest. His process worked great, but my lack of fore sight resulted in less than fabulous results.
Wrapping moulding around three sides of a carcase is cake compared to making the full 360°. Focus on getting one corner good and tight. Then clamp those two pieces in place on the chest and mark the other corner for its miter.
With both miters cut on the front piece you can focus on getting the fit tight on the returns (the pieces that “return” down the ends of your chest).
I leave the returns long until after everything is glued and nailed in place, so don’t mess with those until you have to.
Planting moulding is an art. There are lots of ways to do it; I learned how to do it from a trim carpenter. I drill pilots for my fine finish nails through the moulding and push them into the pilots with my fingers until the tips of the nails protrude slightly (almost nothing) from the moulding.
I fit the miters on the carcase and then tap the nails into the carcase so they bite the carcase. Then I remove the moulding and add glue to the moulding. Glue the entire front of the moulding. On the returns, only glue the miters and the front one-third of the moulding to the ends.
Press everything in place for a minute or two. Then drive the brads. The moulding should not shift. Set the brads. Then saw the returns flush at the back of the carcase. The base is complete.
So why didn’t my mitres close up? I didn’t get my case exactly square and once the nails were in, I was’t able to fix it. Doh!