// Old school not very OOP way to accomplish your task
public object[] MultiReturnMethodOne(string Param1, int Param2)
{
     // DO WORK
     return new object[]{result1,result2,...};
}

public YourClassName MultiReturnMethodTwo(string Param1, int Param2)
{
     // DO WORK
     YourClassName result = new YourClassName(Result1, Result2);
     return result;
}

// OOP Class used in Method 2
public class YourClassName
{
     // declare our private fields
     private string _result1=string.Empty;
     private int _result2=0;

     // constructor
     public YourClassName(string Result1, int Result2)
     {
          this._result1 = Result1;
          this._result2 = Result2;
     }

     // Gets our first Result (string)
     public string Result1
     {
          get
          {
               return _result1; 
          }
     }
     // Gets our Second Result (string)
     public int Result2
     {
          return _result2;
     }     

}

public void testMultiReturn()
{
     // TEST METHOD ONE
     object[] result = MultiReturnMethodOne("test1",10);
     // Now we have our results, but here we dont know exactly
     // what they are so we have to cast them to 
     // their respective types
     // There are more than two ways to do this, but here are the
     // most common
     // Cast One - Common but may fail
     // this method will fail if the result[0] is not a string
     // or if result[1] is not an int
     // so use this in the case that you don't have any question
     // as to the results
     string result1 = (string)result[0]; 
     int result2 = (int)result[1]; 
     // Cast Two - Safer but less informative as to why it 
     // didn't work if it fails
     // safer -- this second method will not fail, but result1 will be null
     // if the result[0] is not a string 
     // or result2 will equal its default value (0) if result[1] is not an
     // integer
   
     result1 = result[0] as string;  
     result2 = result[1] as string;
     // END TEST METHOD ONE

     // TEST METHOD TWO - Preferred Where possible 
     // As Kate said, why not use a class or a struct?
     // See above for definitions
     YourClassName ycn = MultiReturnMethodTwo("test1",10);
     // Now we have a nicer result
     Console.WriteLine("String Result {0}, Int Result {1}",
          ycn.Result1, 
          ycn.Result2);
     // Much more concise, and OOP.
}

return item1 + item2;

public int[] Returnmethod()
{
    int a = 1;
    int b = 2;
    return new int[] {a , b };
}