I've always felt that it was hard to start a new thread here on the WC forum. The option "create post" isn't readily available when causally browsing the forum.....say from the myreply/recentposts pages.
The button to start a new thread only appears once you get into the section that you want to place it in. And for the record, the subsection sneak previews isn't even listed on the page that comes up when you click on the main forum link: https://forums.wincustomize.com/
I'm not saying that it's impossible to find, just that you have to really work to start a post in the correct section.
I would like the create post button to appear at the top of every page in the forum. You could then be directed to choose section and subcategories from there before you start to write. It would just be a more intuitive way of working in my opinion. Having said all that, don't hold your breath for change........yada yada......ya know.....whatever.