Bash aliases can quickly increase your productivity. Define aliases for repetitive commands:

# cd aliases
alias ..='cd ..'
alias ...='cd ../..'
alias ....='cd ../../..'
alias .....='cd ../../../..'

If you always use a command with the same options, alias that too:

alias vlc='vlc --no-video-title --loop --quiet'
alias ls='ls --color --group-directories-first'
alias info='info --vi-keys'

When arguments are needed use functions instead of aliases. To print file size and name sorted by size:

lz() (
    ls -Slhr $@ | awk '{print $5" "$9}' | column -t
)

Good aliases take a minute to define but can save hours of typing in the long run.