Do you need a closed magazine model or an opened one? Or do you prefer a mockup that simultaneously presents both styles? This mockup might interest you because it shows a top view of a closed version and an open magazine together.
One is appropriate for modeling cover graphics, and the other one can present the inner parts. Add your illustrations and texts to these three available spots. You can edit the background to obtain better outcomes. Take advantage of the smart layers, and at the end of the editing process, your results will fascinate you as well as your observers.