There are two well used methods for optimizing coordinated signals: graphical and computer simulation. Traditionally, graphical methods were used on all systems, but now is limited to simple systems. The reasoning is twofold -computer models are complex and often need more information than is actually available. This makes simple graphical methods more time and resource efficient. The other reason for the continued use of graphical methods is so that young engineers may increase their experience and make better decisions using engineering judgment. Computer simulations are very useful for complex systems (such as coordinated grids), or in cases where you are not just optimizing for bandwidth.
To solve a coordinated system graphically, you need to create a time-space diagram that you can edit. You can do that by either drawing parallel broken lines on a computer graphics program or by drawing broken lines (representing red and green intervals in traffic cycles) on paper and cutting them apart. Keeping everything in scale, set some diagonal guides across your "intersections" to represent vehicle speeds. Then you can slide your intersections around until you find the best solution [Roess, et al. 1998].
If you have followed this tutorial through, starting with Basic Signal Timing, you are already familiar with the TSIS traffic simulator. This program is great for simulating systems that have already been designed. Synchro is a simulation package that takes things a step further by helping you optimize signal timing and coordination. The links below lead to Synchro training modules. This is just one program available to help optimize signal timing.