Xara software doesn't have a 'Print Booklet' capability, so you have to use the 'Booklet' setting on your printer if it is available. How I do it is: set up a single page A5 document (so not: 'Double-page') and when I'm ready to print it, choose the 'Booklet' setting with A4 paper size.
If your printer doesn't have imposition capability, you could export your document as a PDF file, open it in PagePlus and take it from there.
Bookmarks