The best way to define a Thread-Safe singleton class in C#

MySingleton.cs

public sealed class MySingleton
{
    private static readonly Lazy<MySingleton> instance = new Lazy<MySingleton>(() => new MySingleton());

    private MySingleton()
    {
        // Private constructor to prevent instantiation.
    }

    public static MySingleton Instance => instance.Value;

    // Other members and methods of the singleton class can be added here.
}