Space between staves

Apologies if this has been answered before.
When creating parts from scores I find it difficult to decrease the space between staves, in order to reduce the number of pages of music. I can drag the staves on page one but have not fathomed how to bring the top stave of the next page to page one. Maybe there is a way to regulate all staves to a certain distance from each other rather than the default.
I find myself reducing the astral size which in turn makes the notation smaller than I would like with vast distance between staves.
I may be missing something very obvious but would appreciate any help in this regard.

Does this help?

And/or this:

I would advise against manually dragging staves around in Engrave mode at all for part layouts, unless there are very specific requirements. If you just want more systems per page, change the settings on the Vertical Spacing page of Layout Options, and/or set a fixed number of systems per page on the Staves and Systems page of the same dialog.

For a tutorial-style example of the things you can do to bring music onto fewer pages, start here in the First Steps guide and follow the pages (the link to the next one is on the bottom right of each page) until the piano piece fits on two pages.

For information generally on how vertical spacing works in Dorico, and how to use the per-layout settings to your advantage, see here:

And for a video that explores these topics, watch these: