Putting wire on and taking wire off is one thing - a means to an end. The reason you do so - BENDING branches - is another thing entirely. Most beginners don't seem to really bend the branches, anyway, beyond an attempt to reposition the whole branch a small bit (for which guy wires are a much better option, IMO) or to add curves so gentle that it doesn't really matter a whole lot the technique or timing.
I think it is a fairly complex subject, without hard and fast rules in many cases. It varies from tree to tree, and from season to season, and from one purpose to another. The basics of technique are found in every beginners' book, and are usually good basic guidelines.
For me, the use of guy wires is much more helpful about 50% of the time. I will even sometimes use multiple guys at various areas along a branch to create curves or angles others would use wrapped wiring on. I can periodically tighten or loosen or re-angle the tension, or shift the placement easily, and they don't leave scars if left on too long. While they are on they will generally look butt ugly, but I couldn't care less, and if I want a photo, I can Photoshop them out easily as I have in many formal photos I've posted here. I can loosen the tension after a while to check to see if the bend has set, and if it has not, I can then recreate the tension very easily compared to unwrapping and re-wrapping the whole branch.
There are many schools of wrapped wiring, some more anal than others, and some more effective than others, and with surprisingly little correlation between those two dimensions, IMO. Single wires or double wires (and exactly how that is done), how wires are anchored, how loose or tight to wrap, whether to use raffia or another wrap or not, copper wire vs coated aluminum wire vs iron wire or coat hangers or whatever you've got lying around or can find cheap, etc.
Timing is important, and has many complexities depending on what you want to do, and on the tree type and your local growing conditions. For instance, on some trees you may even WANT scarring.
The actual bending and placement is the ultimate goal. Do you achieve anything visually pleasing for your efforts or not? Everything else coalesces in this final question, which is more stylistic than technical. But even here there are technical questions. Which trees have branches which bend without breaking, and how much can they be bent - either at once or over time slowly, and how much in different seasons? How long will a bend take to set, and will it then REALLY set or slowly curve back where it was after a few days? Will a broken branch be repairable if you overdo it, or can the effects be mitigated ahead of time with tight wire wrapping or use of raffia? Can you use benders or clamps or hollow out the heartwood to bend otherwise unbendable branches or trunk?
Anyway, just some thoughts. Perhaps they will help more than confuse the beginner. I'd say, just proceed ahead, learn what you can from books, web sites and teachers, practice on as many trees as you can afford, and over time the mysteries will fade into practical knowledge, and beyond. I think perhaps nowhere else in this art are the hierarchical differences between data, information, knowledge and ultimately wisdom any more clear than in this subject.