<?xml version="1.0" encoding="utf-8"?>
<configuration>
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/>
    </startup>

 <appSettings>
  <add key="CRMServerURL" value="http://{{your crm address}}/MSCRMServices/2007/crmservice.asmx?wsdl"/>
  <add key="CRMOrganization" value="yourorganization"/>
  <add key="CRMUsername" value="yuorusername"/>
  <add key="CRMPassword" value="yourpasword"/>
  <add key="CRMDomain" value="yourdomain"/>

 </appSettings>
</configuration>

using Microsoft.Crm.Sdk;
using Microsoft.Crm.Sdk.Query;
using Microsoft.Crm.SdkTypeProxy;
using Microsoft.Crm.Sdk.Metadata;
using Microsoft.Crm.SdkTypeProxy.Metadata;
using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Net;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Xml;

namespace CRMTutorial
{
    class CRMClass
    {
        string _crmserviceurl = ConfigurationManager.AppSettings["CRMServerURL"];
        string _organization = ConfigurationManager.AppSettings["CRMOrganization"];
        string _username = ConfigurationManager.AppSettings["CRMUsername"];
        string _password = ConfigurationManager.AppSettings["CRMPassword"];
        string _domain = ConfigurationManager.AppSettings["CRMDomain"];

        public CrmService crmservice_conn()
        {       
            CrmAuthenticationToken mytoken = new CrmAuthenticationToken();
            mytoken.AuthenticationType = 0;
            mytoken.OrganizationName = this._organization;

            NetworkCredential mycredential = new NetworkCredential();
            mycredential.UserName = this._username;
            mycredential.Password = this._password;
            mycredential.Domain = this._domain;

            CrmService myservice = new CrmService();
            myservice.Url = _crmserviceurl;
            myservice.UseDefaultCredentials = false;
            myservice.CrmAuthenticationTokenValue = mytoken;
            myservice.Credentials = mycredential;

            return myservice;
        }
}

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Crm.Sdk;
using Microsoft.Crm.Sdk.Query;
using Microsoft.Crm.SdkTypeProxy;
using Microsoft.Crm.Sdk.Metadata;
using Microsoft.Crm.SdkTypeProxy.Metadata;
using System.IO;
using System.Xml.Linq;
using System.Xml;
using System.Configuration;


namespace CRMTutorial
{
    class Program
    {
        static void Main(string[] args)
        {
            CRMClass crmclass = new CRMClass();
   //call service you have created
            CrmService service = crmclass.crmservice_conn();
   
   /*
   *your code here
   */   
        }
    }
}