The Spiral Tool can be selected by holding your mouse down on the Line Segment Tool. Once you have created a spiral you like, copy (command/control -C) and paste in front (command/control -F).
Now select the Rotate Tool (R) and click once on the centre of the spiral exactly where the line ends. Now click anywhere else on the spiral and drag to turn the copy slightly. You will now have two spirals coming from the same point but, unfortunately, they will be crossing each other at some point.
To make sure they don’t cross, select the Scale Tool (S), and with one of the spirals selected, just like before click once on the centre of the spiral exactly where the two line ends meet. Now click somewhere on the outer side of the spiral and drag to size the spiral so it doesn’t cross the other anywhere. (This takes a bit of doing, you’ll find it much easier if the decay percentage of your spiral when the Spiral Tool is double clicked.
All that remains is for your two end points to be joined (command/control -J) and now your twirl can be filled in with a colour and used.
There is another way. Create a 10 pixel triangle and copy it. Go to you Brushes palette and select New Brush… and choose Art Brush, make sure the arrow points the same way as the triangle. Then, after you’ve drawn you’re spiral, give it a stroke value and apply your new brush. The triangle will be applied throughout the length of the twirl and this way you get a more perfect looking spiral.
In fact, this spiral can then be set as a new Art Brush and then you can experiment applying this spiral to lines to create differently distorted spirals! Happy twirling!