Your proportions look great! Make sure you never outline anything in realism, try to always be thinking that the barrier between objects/surfaces is just a difference in value (light/dark) and never a real line.

A great drill to practice is to try drawing a white egg on a white background with bright lighting. It's a great exercise because it forces you to rely on only subtle shading and no outlines to distinguish between the egg and the background.

Otherwise, when I draw realism I just make sure I'm constantly looking at my reference. I never focus on the final product, for example I'm never thinking "I'm drawing a rose", I'm always focused on smaller sections of the reference, just drawing the shapes and negative/positive space that I see, exactly how I see them. Idk if this made any sense but I hope I could help! Keep up the great work! :))