Tom Rudolph, a guru on using music technology in education and co-author of a book about getting the most out of Sibelius
Arrange is definitely a very sophisticated and useful tool, but it can be pretty daunting when you first get started with it. Tom shares some tips that will have you up and running with it in no time.
My own personal favourite tip regarding Arrange is that sometimes, for simple operations, you’re better off not using it: for example, for simple explode (splitting notes from one or two staves onto more staves, distributing the notes sensibly) and reduction (condensing notes from many staves down onto one or two staves) tasks, the dedicated Explode and Reduce plug-ins in the Plug-ins > Composing Tools submenu are actually better-suited for these tasks, so don’t overlook them.
Where Arrange really comes into its own is where you want to automatically split different kinds of material onto different instruments, e.g. to put the melody line in the wind and accompaniment chords in the brass. Arrange can take a complex texture on, say, a piano instrument and split it into its constituent parts to distribute them onto other staves, which is very cool – but it is a tool that should be used with care, as nothing that Sibelius can do for you automatically is any substitute for learning the skills of arranging and orchestrating for yourself.