Yes, you should on your key articles anyway. I would go through this board - there are an abundance of great techniques. Choose some of the more recent for ALL platforms and give them a try. Don't waste a lot of your effort on IG for what you're looking to do. Try Canva which is free and quick to churn out different social media graphics. They have a paid plan, but free is good, too. Plus, they already have the recommended sizes included.
All I am saying is I highly recommend - FOR TRAFFIC back to site, not focusing solely on IG. You will not be a happy camper (unless you have great luck!:). It just takes strategy and game plan, but use as many platforms as you possibly can.