

With a simple technique you can round the edges of anything in Illustrator. With the Graphic Styles Panel you can reuse your style over and over again.
The Method
In this example we will curve the edges of a star. This technique can be used on most objects. First we have to draw a star with the Star Tool. The star has a pink fill and an orange stroke of 5pt.

Select the star and navigate to Object > Path > Offset Path. In the dialog box turn on the Preview option to see the preview. Choose an offset of 3pt and pick Round for the Joins. This will round off the edges. This will produce a new star with rounded edges.

The two stars are still on the canvas. Move one to the left and you should see something like this:

You can delete the original star leaving only the star with rounded corners.
Reusing styles
To reuse the rounded edge style you just created using the Graphic Styles panel. To open the Graphic Styles Panel navigate to Window > Graphic Styles. Then drag the rounded edge star in the Appearance Panel. The style will be added to the default list.
Now you can reuse this style with other elements in your design. Create some text and select it. Then click on the Graphic Style. The rounded edges and colours get applied. You can still edit it through the Appearance Panel. In this example I reduced the stroke a little.

Now, with the style in your Graphic Styles box it is easy to give a curved edge to almost anything. Here's another example. To give curved edges to this button just click the Graphic Style.
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