Hey chief. I'm a new grower myself, so of course you should take anything I say with a grain of salt, but I read somewhere that it's best to start tying between the fourth and fifth nodes. That's how long I waited, and by that time my bigger ladies (hopefully) had nice thick, strong main stems. I would suggest a strategy that has been working beautifully for me, which is to do it a few inches per branch per day. For example, from straight-up I will tie my ribbon (cheap, soft, flat, excellent) around the stem with a little lasso knot (for easy removal if necessary) and pull gently to see how far I think I can tug it. I usually go just a tad less than that. So from 90 degrees in an evening I might pull it to 70 degrees, then the next day pull it down to 50 or so. I follow the same rules when dealing with branches which need to be tied to keep them from brushing against the lights (tight dresser grow). I also add new lines every two or three inches depending on how far the stem has stretched since the last tie. So for example, right now my biggest plant in veg (6" pot, one month old) is tied in three places: one around the middle of the stem, to get it down to the proper horizontal orientation; another two nodes up to keep things straight; a third to hold down a particularly pesky fan leaf which wants so badly to burn itself on a light. The plant is probably a quarter to a third of the way around the edge of the pot right now. If it makes the final cut (read: is female) I will put it in an 8" pot (don't think I have room for 10") and let it breathe a little before beginning the tying process again to accommodate the larger space.
Don't know if any of that helps you or not. I certainly hope this isn't the junior trying to lecture the senior and I wind up looking like a fool! Also I'm lit.