I would like to have a default shipping method selected from the moment I put a product in the basket.

In my "Add to basket"-macro I run the following code:

if ( !SiteContext.Current.OrderContext.HasBasket )
{
    var newbasket = SiteContext.Current.OrderContext.NewBasket(catalog.PriceGroup.Currency);

    // Select default shipment method
    var shippingMethod = SiteContext.Current.OrderContext.GetAvailableShippingMethods().FirstOrDefault();
    TransactionLibrary.EditShipmentInformation("shipping", "", "", "", "", "", "", "", "", "", "", "", "", Country.All().First().CountryId);
    newbasket.PurchaseOrder.CreateShipment(shippingMethod, newbasket.PurchaseOrder.GetShippingAddress("shipping"), true);
}

var basket = SiteContext.Current.OrderContext.GetBasket();

var order = SiteContext.Current.OrderContext.GetBasket().PurchaseOrder;
var orderline = order.AddProduct(catalog, product, quantity, true);

var shipment = basket.PurchaseOrder.Shipments.First();
shipment.AddOrderLine(orderline);

PipelineFactory.Create<PurchaseOrder>("basket").Execute(basket.PurchaseOrder);
TransactionLibrary.ExecuteBasketPipeline();