I start Emacs in "server-mode" alongside my graphical environment. Whenever I want to use it, everything is already loaded and ready to go. Thanks to that, from my perspective it opens pretty much instantly.

It can be easily set by editing ~/.xinitrc file. This file is being used by xinit(1) to start the X Window System server and a first client program.

# .xinitrc
# ...
emacs --daemon
# ...

According to emacs(1) the emacs --daemon command starts Emacs as daemon (o rly?), enables Emacs server and disconnects from the terminal.

With server running in the background, I can connect to it with the emacsclient(1) command.

% emacsclient -c -a ""

To create a new frame, the flag -c is used. This is particularly useful when Emacs is already open but I don't want to reuse the existing frame. The second flag, -a, initiates an alternate editor if the Emacs server is not running. If it is left empty, as in this case, it runs emacs --daemon and attempts to connect to it.

To make my life easier, I've placed that line in a file named ec, made it executable, and saved it in a directory within my PATH (/usr/local/bin/, to be specific). Now, I can launch Emacs client just like any other program.