Steps I use to make world on FreeBSD:

1. Install cvsup-without-gui

# cd /usr/ports/net/cvsup-without-gui

make install distclean

2. Update the source files

# cvsup -g -h /usr/share/examples/cvsup/stable-supfile

3. Configure a kernel

See Configuring the FreeBSD Kernel in the FreeBSD Handbook

4. Grab the Makefile

# mkdir /root/make

cd /root/make

fetch wp-dev.clarksys.com/freebsd/Makefile

5. Make World

# make world

6. Make your Kernel

# make -DMYKERNEL= kernel

7. Merge the updated configuration

# make merge
That’s it, you now have a freshly updated system.
Check out the FreeBSD Diary for a more indepth look at the make world process.