While I’m working, I always have a minimum of 3 or 4 open terminals: one for watching the logs, one for ssh and so on.
It’s not good to have a lot of windows open, and tab switching can be a pain, specially when you want to see what’s going on in one window while you type in another one.
So I’ve found recently Terminator.
Taken from terminator’s home page:

The goal of this project is to produce a useful tool for arranging terminals.
It is inspired by programs such as gnome-multi-term, quadkonsole, etc. in that the main focus is arranging terminals in grids (tabs is the most common default method, which Terminator also supports).

Much of the behaviour of Terminator is based on GNOME Terminal, and we are adding more features from that as time goes by, but we also want to extend out in different directions with useful features for sysadmins and other users. If you have any suggestions, please file wishlist bugs! (see below for the address)

Features:

* Arrange terminals in a grid
* Tabs
* Drag and drop re-ordering of terminals
* Lots of keyboard shortcuts
* Config file to override gnome-terminal settings
* Simultaneous typing to arbitrary groups of terminals

My screen.

My screen.

You can put your default configurations in the file ~/.config/terminator/config
Mine configurations are this:

#/home/mauricio/.config/terminator/config
enable_real_transparency=True
force_no_bell=True
scrollbar_position=disabled
titlebars=False
handle_size=1

This increased a lot my productivity. Unfortunately I haven’t found anything like Terminator for Mac.