Gardening

The reason being that they will usually bloom just fine with no pruning whatsoever, and maybe even better if you aren't pruning them correctly as they bloom quite well on old wood. However, many of the same rules apply that work for pretty much all flowering shrubs, such as deadheading, removing crossing branches, and clearing out dead and dying wood.

Here's a good cut-to-the-chase article from a true master that I think makes a lot of sense for developing a good strategy.
http://ucanr.edu/datastoreFiles/268-86.pdf

Can't help you with the rusty nails thing. Iron deficiency can be a problem, and I suspect there are better soil additives that can be used at least in the short term, but I've never tried using nails.