there are many ways one can LST, your drill and tie string method works perfectly but there are also other ways like:
using christmas tree ornement hangers along with your desired weight fishing anchor, also you can use short pieces of thicker guage wire preferable 14 guage up to 10 guage. depending on size of branch this method works well. there are many ways to do it, but when you do just make sure that you arent completley pinching over the pbranch that your lsting, but thats a common sense thing that you already know... some times you can just get creative!
over time of being held to grow in a certain way the stalk will actually retain that shape, as seen in allot of bonsai plants, so that more permanent way of drilling hole and string arent always necessary.
just my 2 cents though, the ladies are looking good!