If you are serious about a career in design, the absolute best thing you can do right now is to get yourself a job at a studio working for experienced designers who are willing to teach you the parts of the trade you didn’t get in school. A good designer understands that part of their role is to teach the next generation.
Use powerful images — those trigger emotions and correspond with your product or service. Don’t just simply tell them how great you are when it comes to solving their problems, show them! While stock photos can be “comfortable” solutions but you should look for real life scenarios with real people involved instead. Doing so will build social proof.