Tip #1: Follow the employers whom you want to contact or get contacted by. Hiring managers love to ask employees within a company for recommendations to fill open positions. After following the companies you’re interested in you can also follow some of the people who work there, whether they work in HR or not. Either way will increase your visibility to hiring managers or recruiters. If you strike up a conversation with any of the employees, and it goes well, that could lead to an introduction (aka referral) by the employee, on your behalf, to a recruiter down the road. You could of course also just add a recruiter directly on LinkedIn.
Tip #2: Make sure you are putting in the work on your end, aka make sure your LinkedIn profile is in great shape. It should have a recent, professional looking profile picture, all relevant education/certification information, relevant work history, and endorsements from others on LinkedIn where appropriate. The most serious recruiters know how to do keyword searches on LinkedIn, so making sure your profile is keyword optimized, or learning how to do so and then doing it, would also be beneficial.
Tip #3: Don’t quit your previous employer just yet. If it was a situation where you just had to go, or were let go involuntarily, obviously there’s no changing that now. But in general recruiters prefer candidates who are currently employed. It is kind of ironic, but also logical at the same time, because it shows (or at least increases the odds) that an employee has up-to-date skills, doesn’t have anything preventing them from being employed (criminal activity, drug issues, etc.), and that they get along with others (or they would’ve been fired already). If you’re already unemployed, it’s best not to hide it, but to have the best answer possible when asked by a prospective employer.