Book multiple services on one invoice

Is the only way to group multiple services on one invoice by doing repeat booking for each serice? i.e., if someone wants 2 short walks and 4 long walks on the weekend and I just want to invoice them after all are done and discount a single invoice, would they book 2 repeating short walks and 4 repeating long walks and it's going to make 2 invoices? Or is there a more efficient way?