I tend to be with Sean. I'd do this:
Table1
ID INT
more columns
Table2
ID INT
FKID INT
where I'd name the FKID something that makes sense.
Or more formally:
Create table Customers (
CustomerID int
, CustomerName Varchar(20)
)
;
Create table Orders (
OrderID int
, CustomerID int
, OrderDate datetime
)
;