Putting together a news bulletin is like preparing a satisfying meal; it needs to be balanced and digestible. The main factors are importance, length and pace.
Clearly, the most important stories must go first; it is essential that listeners hear these as soon as possible. However, too many long and serious economic or political stories at the start can make your bulletin ponderous. For example, a string of stories about a street fight or a party argument might bore your audience to the point of switching off.
This is why it is important to keep the pacing of the bulletin fast, using short grabs and actuality pieces. These should be no longer than 40 seconds and clearly written, to help your listeners follow the story. Grabs should be re-edited if necessary to reduce their duration, for instance by changing the music or cutting out some of the speech. It is also advisable to use a variety of voices and accents; this can make your bulletin sound more authentic and credible.
If you have some less important stories which you want to mention, it is usual to run them as briefs at the end of the bulletin. These should not be used to fill up time, but simply to remind your listeners that you have reported on something which is going on in their area or country. Similarly, closing headlines should be brief reminders of the major stories which have been covered.