Some times you write classes, inherit from them and create properties to cast things from base class to your known types.

Like this

public abstract class BaseClass
{
    private SomeClass backingField;

    public SomeClass Property
    {
        get { return backingField; }
        set
        {
            if (backingField == value)
                return;
            backingField = value;
            // do other stuff
        }
    }

    public BaseClass(SomeClass someClass)
    {
        Property = someClass;
    }
}

public class DerivedClass : BaseClass
{
    public OtherClass Derived => (OtherClass)Property;

    public DerivedClass(OtherClass otherClass) : base(otherClass)
    {
    }
}

And you know that this is a huge amount of stuff you have to keep up with (every new derived class needs a property like this if you want it to strongly typed). My solution to this is simple: Just create a generic gerived class and new-override the Property.

public abstract class BaseClass<TClass> : BaseClass where TClass : SomeClass
{
    public new SomeClass Property
    {
        get { return (TClass)base.Property; }
        set { base.Property = value; }
    }

    public BaseClass(TClass tClass) : base(tClass)
    {
    }
}

And your derived class now looks like:

public class DerivedClass : BaseClass<OtherClass>
{
    public DerivedClass(OtherClass otherClass) : base(otherClass)
    {
    }
}

Simple enough for every project to implement this. Has been a massive time saver in one of my projects.