Its possible that some of my class members will not be initialized when one of my virtual members gets called even before the constructor. How can I avoid this?

If possible, initialize them in-line:

	public class MyClass
	{
		public ArrayList myArrayList = new ArrayList();

		public MyClass(){}
	
		public override void MyOverride()
		{
			// When this gets called by the base class constructor, myArrayList will be initialized.
		}
	
	}