Create valid .config from Custom ConfigurationElement classes

Question

Does anyone have a good technique for generating a valid xx.config file after you have finished creating your

public class XXXConfigurationElement : ConfigurationElement
{

    [ConfigurationProperty("blabhblahblah", IsRequired=true)]
    public YYYConfigElement Foobar
    {
        get { return (YYYConfigElement )base["blabhblahblah"]; }
    }

}

classes with all the ConfigurationProperty attributes set up?

perhaps using something in snippy in reflector?