The music game is a non stop ride. Don’t assume you’ll get big of one project and that’ll be you set for life, even the biggest stars have to follow up with fresh material all the time. You should ideally start writing (Or at least start thinking about) new material once you’ve finished recording your first project, if not before. The reason for this being it can take a while to get together new material, and you don’t want to leave too long before your follow up release. Staying out of the public eye for too long can cause people to forget about you, and people will generally only follow you for so long without giving them something new. This of course has exceptions, but unless you’re a big super star, don’t expect this exception to apply to you.
One way to keep your name out there is promotional materials. If you give out a free ‘download only’ tune every now and then or free wall papers for people’s computer, you will keep people coming back to your website and in turn read up on the latest news happening with you.