Coding Best Practices - 1

If the derived classes(or concrete/specialized classes) cant make use of all the functionalities (100% usage) of its base class(though it is a 'is a kind of' relationship among them, then prefer delegation/composition over Generalization/inheritance.

//Bad Practices
public abstract class BaseClass
{
abstract void Method1();
abstract void Method2();
//Some more methods....
}
public class Derived : BaseClass
{
public override void Method1() { //Some processing... }
public override void Method2() { //Actually this derived class doesnt need this method2...but since it is abstract in its base class, i have to override to getout of compilation issues... }
//Some more methods...
}

Best Practice

public class BaseClass
{
public void Method1() { //Some processing }
public void Method2() { //Some processing.. } //Some more methods....
}
public class Derived
{
private BaseClass objBase;
public Derived():this(new BaseClass()) { }
public Derived(BaseClass obj) { objBase = obj; }
public void Method1()
{
objBase.Method1(); //If needed some more derived class processing... }
//Some more methods...
}

I hope this helps!.

Regards,
-Vinayak