"cd -" and also using "cd" with no arguments to get back to $HOME are great tips. I also have a bash function called "up" to get back N directories up the hierarchy so I can do "up 5" which is like "cd ../../../../.." but much easier to type.

    up () {
        if [[ $# -eq 1 && "$1" -gt 0 ]] ; then
            local i d
            for (( i = 0; i < $1; i++ )) ; do d="../$d" ; done
            cd $d
        else
            echo "Usage: up N"
        fi
    }