Basically, look to see which headers and libraries the package needs
and include the respective buildlink3.mk files. ;)  One special case
to note is that libXext's b3.mk doesn't pull in xextproto, so if
that's needed, it must be explicitly included.  For your
run-of-the-mill gtk2 application, x11/gtk2/b3.mk itself often includes
all that's needed.

If you're ever unsure of which package to include,  you may use
pkg_info -F on a file in ${LOCALBASE} to see, for example, which
package a header belongs to.

It appears that the packages you mentioned have been updated.  Are
there any other packages which you're having issues with?

--Blair