Config options with pkg

[Robert Fitzpatrick]

I don't do a lot of upgrades or installs, so my use of the new pkg way 
of doing things is limited right now. I've been trying to find 
instructions for how to configure options for packages. Right now I'm 
dealing with a new install of Postfix and trying to get LDAP support. Of 
course, I can move into the ports directory for the package and 'make 
config', but get the warning that I should use pkg. Can someone point me 
to the instruction I'm lacking for this or suggest how to configure 
package options with pkg?

Thanks!
-- 
Robert