You can post a message for your followers directly from the home page.
Click on the text field just underneath the home page photo gallery with the words "What are you working on?" in it.
This will pop open the dialogue below and from here you can share a photo, a text update or both with your followers.
If you click on the dropdown menu underneath the text field you have the option to post your message to your followers, or directly into one of the Advice boards. Select your preferred destination and then click "Post" to share your message.
You also have the option to post an update to your followers on your profile page. Simply click on the 'Your Houzz' icon in the top right corner of the website and click on the text field underneath your Projects and Ideabooks.