LFS and BLFS do have a different approach. With LFS you start at page one and work through the book page by page.
With BLFS you first need to do chapter 3 (after reading 1 and 2). After that it is up to you to install what you want/need. If for example you want to install an ssh server you got to Chapter 19. Major Servers - OpenSSH-5.6p1
You check the dependencies (the required ones must be installed) and install these first (if you haven't already). In the above example, OpenSSL-1.0.0b must be installed before you start with ssh. Depending on your needs and wishes you might want to install the other optional dependencies.
The building and configuring is done the same way as LFS: All the needed steps are present in the chapters.
Just to make sure: You do not need the chrooted environment any more: Start your newly build LFS system and start expanding.
Hope this helps.