Drawing a Quatrefoil

At first glance, this design looks like it should be an easy one. After all, putting four circles together seems straightforward enough. But, as it turns out there's a catch. If you make the circle's border too thin or too thick, the design just doesn't work. Fortunately, I have a few solutions to help you get that right. Firstly, if you're working on a computer, go use this tutorial to make things super easy. Alternatively, you can try using a grid to make this design:

An example of making a quatrefoil using a grid

Don't have a grid handy? Here's how to make this symbol by hand:
Illustration of step 1 Start off by drawing a very large plus.
Illustration of step 2 Draw lines from the center of each arm until they meet, forming a big square.
Illustration of step 3 Now, what you've really done is make a set of four connected pluses. Mark off the last fourth of each arm on the top plus.
Illustration of step 4 Continue on by adding similar marks to the other three pluses.
Illustration of step 5 Now that the layout is done, use the marks and the ends of the pluses to guide you in making the eight circles making up the quatrefoil.
Illustration of step 6 Erase the area marked in green.
Illustration of step 7 Tidy things up a tad and your quatrefoil is complete!