Building software from ports takes quite a lot of time, especially when using bulky programs like ImageMagick or Apache. For example, if you install ImageMagick you will notice that this program has a lot of dependencies. Dependencies are programs which need to be installed before ImageMagick can be installed; ImageMagick can't work without them. The hardest thing about installing ImageMagick is that you need to be in the vicinity of the computer to confirm the installation of each dependent program. Installation will be delayed until you click "OK" to confirm the installation of every dependent program (by this action you confirm options of the current program). (source)
I could not say it better.
The article is useful, but, as for me, the best was the Dola Marco's comment, which suggested to run:
# make config-recursive
# make -DBATCH install clean
I have tried it and it worked. I ran those commands against Xorg and it was successfully installed while I slept. Cool!
I suppose, starting from today, it will be the only installation method at all for me.
Best regards.
P.S. There is some additional information about ports configuration. It is in Russian.