After you cd to the base directory, use go build ./... Note that there are 3 periods as it is an ellipsis. This will recursively build all subdirectories. Of course you can always do go build path/to/my/base/... from wherever without needing to cd to the directory.
This is very useful for those who use an IDE that relies on the go/pkg directory, such as SublimeText3 with GoSublime. Making changes to a dependency package won’t update the autocompletes until you build the package, which places it in the go/pkg directory.
My own projects are broken into a multiple package structure, so I frequently have to go build ./... to update my autocompletion.