While I got familiar with WordPress and became a programmer despite my intentions, I learned how to turn WordPress into a great and easy collaboration tool.
I believe in simplicity, I do not believe in paid online tools. Most of the online wireframe builder platforms and collaboration tools waste your money and require extra learning curves for everyone in your organization, when a simple wireframe can also be created in an online shared PPT using shapes and slides.
Instead of wasting your time finding the right online tool you can turn WordPress (or any other CMS) into a great collaboration tool for working together with copywriters and marketers. With minimal effort towards others in your company, you can reduce the time being spent on meetings, not to mention all the re-dos and cancelled solutions. So here is what you do: besides focusing on creating and coding a responsive website, use the following simple tools from the beginning of the website development process.
Provide different colour-coded markers for the editors (even in the text editor interface). You can choose different colours for temporary or place-holder texts and notes:
Big fat image labels
When you can use placeholder images as well, you may want to provide a possibility for the editors to put a clearly visible label on it. This way everyone will know what this image is supposed to be about, so copywriters can write better content and vice versa.
Sometimes marketers tend to divide the website into several (way too many) subsections. This habit makes the overview of the entire, full content difficult. What you might want to do is mark and hide subsections until you have final and approved content (open/close on interaction, make subsections semi-transparent). This way everyone can see all related content at once, without having to waste their time clicking for subpages. When all the content is ready, editors can decide about splitting it to sub-pages.
Keep it human
Do not forget that you are working with non-programmers. Instead of boring people with teaching them about “sortcodes” and “custom fields”, create an easy to use interface.