One big fat DTO vs multiple skinny DTO

I'm always struggling with naming convention and design pattern for my application, it's been very hard to keep it consistent, so I have a simple case, let's say I have a service with method called CreateOrder

public OrderDTO CreateOrder(int customerID, OrderShipDTO shipping, OrderDetailDTO products);

Here's the DTO class

    public class OrderDTO
    {
        public int ID { get; set; }
        public decimal PriceTotal { get; set; }
        public string Status { get; set; }
        public string PaymentMethod { get; set; }

        public OrderShipDTO OrderShip { get; set; }
        public ICollection<OrderDetailDTO> OrderDetails { get; set; }
    }
    public class OrderShipDTO
    {
        public string Name { get; set; }
        public string Phone { get; set; }
        public string Address { get; set; }
        public string Province { get; set; }
        public string City { get; set; }
        public string District { get; set; }
        public string SubDistrict { get; set; }
        public string ZipCode { get; set; }
    }

    public class OrderDetailDTO
    {
        public int ID { get; set; }
        public decimal Quantity { get; set; }
        public decimal Price { get; set; }
        public int ProductID { get; set; }
    }

As you can see, my method CreateOrder will return OrderDTO and accept OrderDetailDTO parameters, but the method actually only requires property OrderDetailDTO.ProductID and OrderDetailDTO.Quantity for the business logic calculation.

So, it feels not right for me (and confusing because I wasn't sure which properties need to have a value and which doesn't) to pass the entire OrderDetailDTO object even though it only needs 2 of the properties to be filled, but I still need to pass back the OrderDTO which will include ICollection<OrderDetailDTO> because I need to get the OrderDetailDTO.Price value and show it to my customer.

So I was thinking of creating another DTO like this

    public class OrderDetailDTO_2 //temp name
    {
        public decimal Quantity { get; set; }
        public int ProductID { get; set; }
    }

But I will end up with a lot of DTOs and even though I'm fine with it, what's the best practice for the DTO naming?