Once you know what you want, it's time to find out what the companies you're applying for want.
Check on a company's Glassdoor page. It will help you get a feel for their company culture, figure out what questions they commonly ask in interviews, and even discover what salary you're likely to be paid. But keep an open mind. Glassdoor is the Yelp of companies - it doesn’t show the whole picture.
Do a general Google search and if the company is in the news. Make note of what’s topical.
Study the company’s website. Do a deep dive and read every word.
Check the LinkedIn page, find out who’s who. You might find you know someone and score a contact.