I use @Hafta 's CST - Constant Stress Training Method (sort of).
I use the "bullet style" fishing weights and use a half un-bent paper clip to hold the weight on one end and hook over the branch on the other. I'll use some combination of three different sizes of weights, usually the heavier ones closer to the main stalk where the branch is the strongest and lighter ones out toward the branch ends. I use the quadlining approach and try to keep the branches relatively flat.
The weights hold the branch roughly in position but allow some movement which is supposed to build stronger branches without the tension that can cause breaks when using a fixed restraint like ties as the branch fights against it. The branches are already pretty robust in a SIP but I like the flexibility.
I take them off if I foliar and then reset, and use use them in conjunction with BBQ skewers to help set lateral direction when I want to better space out the branches.
I kid ladies, I kid! For real though, I'd be surprised if there were more than golfballs when she finishes up, smells nice though. 
I hope she tastes as good as she smells. I neglected the addition of the carbon filters, opting for greater negative pressure airflow instead, and this was a mistake. Even an old skunk with mange would lift his nose and sniff around for weed if he wandered within 100 feet of my backup grow box.