Debian 5.0 (Lenny) onwards sets apt-get to install "recommends" packages by default, which can result in hundreds of MB of unnecessary software being installed.
/etc/apt/apt.conf.d/01norecommendcontaining the following lines:
APT::Install-Recommends "0"; APT::Install-Suggests "0";This is best done as early as possible in a new installation. Running
apt-get autoremoveshould then remove any "recommends" packages that were installed previously. It will prompt with a list of packages to be removed. Check the list and if there are any you want to keep, install them manually with apt-get.