Some useful APT options   Recently updated !

apt by default reads files in /etc/apt/apt.conf.d/, so you can create a file for each line if you like to or create a new file in there and put them all in:

Acquire::Check-Valid-Until "false"; #problems with not up2date mirrors, release file expired?
APT::Get::AllowUnauthenticated "true"; #allow installation of unauthenticated files
GPG::Check false; #disable all GPG checks by default