A basic ~/.tmux.conf for the OS X Terminal.app.

.tmux.conf

set -g default-terminal "screen-256color"
set -g status-bg white
set -g status-fg black
set -g status-left " "
set -g status-right " #(hostname -s) "
set -g set-titles on
set -g set-titles-string "#W"
set -g base-index 1
set -s escape-time 0

# Install:
# 1. Download and install: https://github.com/norio-nomura/EasySIMBL/
# 2. Download and drag bundle into EasySIMBL: https://bitheap.org/mouseterm/
set -g mouse-select-pane on
set -g mouse-select-window on
setw -g mode-mouse on

# Install:
# brew install reattach-to-user-namespace
set -g default-command "reattach-to-user-namespace -l zsh"