For many years I was involved in organisations who relied on obtaining free publicity via local radio and newspapers. During that time I learned a few rules from personal experience and observation. Many of them have been confirmed in conversations with others I have met.
If you are targeting the "press" there are a few simple factors to consider.

1) Newspapers like a photograph. An article with a picture is more likely to get in than one without.
2) Copy writers are lazy - if you send something that can go straight in without them having to actually write anything themselves it saves them time and effort.
3) Copy writers know nothing about music - especially the ones who do the music column - they are usually there because they can't manage to compose a believable horoscope. Something pre-written and short will go in easily (see point 2). If it is too long they may try to edit it or re-write. If they do this they will inevitably miss out all the important information like the name of the performer, what they play or the type of music they sing. Make sure they NEVER have to even consider altering what you have written to make it fit a smaller space.
4) Frequently if an publicity release is longer than the space available, they will simply print from the start, up to the end of the available column. Anything you have written beyond this point simply disappears. It is very annoying when they tell their readers all about the performer and then omit where and when they are playing.
The usual remedy to this is to make certain that ALL important information - names, dates, times, places, who to contact for information etc. is written in the first two paragraphs. You can then follow with a more detailed biography, but if some of this is cut at least you have SOME useful information in the paper.
5) If your performer has some unique "selling point" emphasise it. When doing publicity for the Topic Folk Club, (Bradford, UK) in the early '80's, I frequently had to invent a biography due to lack of an artiste's own blurb. It is often not easy for a "Folk" performer - plays guitar and sings traditional/their own songs. How do you make that read differently for the 100th performer who fits the description?
Quack
GtD