Showcase your work experience by mentioning prior positions and recommendations. Use keywords to build your brand and locate prospects, use them the most in the headline, current experience and past experience areas so they can be searched easily.
In your summary, start with your role and not your name, and make sure you list out all your specialities. Ensure your headline also specifies your role or designation. It is best to keep your profile public so it shows in search results.
Provide links to your portfolio site or blog. Where you have the option to add links, choose 'other' and mention the name of your site rather than choosing the 'my company' option that is already provided.
You can also drag and drop the different category boxes so use summary first followed by your skills and then your endorsements from other professional contacts.
This one is something I don't do much but it does make sense to try - use the events schedule to show where you are headed if people want to network with you.
Use apps like Slideshare, reading lists, and box.net for sharing tips etc.
Status updates are the latest new feature, you can link this to Twitter for simultaneous updates, or share it on groups and even comment on updates that others share.
Hopefully some of these pointers help you!