I've spent many years marking MBA reports for students. Here are the most common mistakes and how to avoid them.

The Executive Summary acts like an 'abstract' that you see in an academic journal article. It summarizes the entire report for the busy 'executive'. Thus, it needs to include: purpose of the report, (aim), how the author(s) went about generating the report (i.e., research methodology); the findings, conclusions, and any recommendations. A quick way to put something together is to copy-and-paste the 'summary' from each major section (or chapter); although this assumes the author(s) have written a proper summary for each section (or chapter).

Every new Heading level 1 in a report needs to start on a new page; except TOC, LOI. Also, generally speaking, the TOC does not include the headings for the Front Matter.

By auto-generating the Table of Contents from the headings, you can be assured that the TOC matches the body and that the page number is correct.

All images and tables need to be listed as part of the 'content' (i.e., after the table of contents). Only blogs and academic articles (i.e., essay style) do not include a List of Figures or List of Tables. 

The body of the document is the start of the report proper; hence the page number needs to start from 1. This is why the Front Matter uses roman numerals for its page number.

All images and tables in a report need a caption, and captions should be numbered. If they are numbered, include a list in the 'content'. Only blogs (or news articles) have unnumbered captions. 

Images that are not created by the author(s) need to include their source citation; otherwise copyright theft is occurring. Images without a source are assumed to have been created by the author. Any changes to someone else's image needs to clearly state in the source details 'Adapted from...'

Images plonked on a page, and not discussed in the body of the writing, make no sense to a reader because the reader is not 'informed' about their presence and what makes them worthy of inspection; they act as 'adornments' only, and are, therefore, irrelevant to the argument being mounted. If an image or table is important, then the author needs to tell the reader about it. This is why captions were invented; so an author can 'refer' easily to a specific image (see Figure 3).