Since LinkedIn is specifically about making professional connections, this is the only network where every update you make can be about your profession. No one would think you're being fake or conceited. Share regularly, but keep in mind posting too frequently could cause people to disconnect from you.
There are also many professional groups with a LinkedIn presence. Join several groups related to your industry. Participate in conversations within the groups regularly. Being a member, but not contributing, does nothing for you. Social media is all about the conversation!
LinkedIn also allows you to share your slideshows, connect to your blog posts and share information on your business travels. All of these can work as an advertisement for who you are and what you do. Use them! Just make sure you're not breaking an NDA (non-disclosure agreement) with any of those materials.