Choose the split method based on the job
Splitting every page is useful for forms, certificates, answer sheets, and scans where each page needs its own destination. Section splitting is better when pages belong together: one chapter, one student's records, one invoice batch, or one signed agreement with its attachments. The point is not to create as many files as possible; it is to give each output a clear reason to exist.
Look for natural boundaries before setting a break: a cover page, a new heading, a repeated name, a blank separator, or a signature page. The visual preview makes this less error-prone than typing page ranges from memory. If the source contains a mix of portrait and landscape pages, keep them together as they are; a split should change grouping, not the content itself.