WCF ChannelFactory

public static class WcfExtensions
{
    public static void Using<T>(this T client, Action<T> work)
        where T : ICommunicationObject
    {
        try
        {
            work(client);
            client.Close();
        }
        catch (CommunicationException e) { client.Abort(); } catch (TimeoutException e)
        {
            client.Abort();
        }
        catch (Exception e)
        {
            client.Abort();
            throw;
        }
    }
}

Then use this instead of the using keyword:

new SomeClient().Using(channel => { channel.Login(username, password); });

Or if you are using ChannelFactory then:

new ChannelFactory<ISomeService>().Using(channel => {    
    channel.Login(username, password);
});

Reference: http://www.codeproject.com/Tips/197531/Do-not-use-using-for-WCF-Clients
http://www.codeproject.com/Articles/361660/WCF-Proxy-Manager-Going-Configless