I've cobbled this together from reading different tutorials and such. I'm a tmux noob, but this seems to get the job done for me so far. I run it in iTerm2

.tmux.conf

# Set prefix key to Ctrl-a
unbind-key C-b
set-option -g prefix C-a

# tell tmux to use 256 colour terminal
set -g default-terminal "screen-256color"

# Key bindings

# navigate panes using jk, and ctrl+jk (no prefix)
bind-key -r j select-pane -t :.-
bind-key -r k select-pane -t :.+
bind-key -r C-j select-pane -t :.-
bind-key -r C-k select-pane -t :.+

# navigate windows using hl, and ctrl-hl (no prefix)
bind-key -r h select-window -t :-
bind-key -r l select-window -t :+
bind-key -r C-h select-window -t :-
bind-key -r C-l select-window -t :+

# swap panes
bind-key -r J swap-pane -D
bind-key -r K swap-pane -U

# Statusbar settings

# default statusbar colors
set -g status-fg white
set -g status-bg default
set -g status-attr default

# default window title colors
setw -g window-status-fg white
setw -g window-status-bg default
setw -g window-status-attr dim

# active window title colors
setw -g window-status-current-fg cyan
setw -g window-status-current-bg default
#setw -g window-status-current-attr bright
setw -g window-status-current-attr underscore

new-session -s dev