A part of me is mortified to show how dirty my microwave can be but I wanted to share a great cleaning tip I got years ago. Sometimes, I have a small amount of white vinegar left in the bottle. You can also use red wine vinegar or cider vinegar. I pour 1/4 cup of the vinegar in a mug of water like the one in the photo.
I microwave it for about 2-3 minutes. It creates a high humidity inside which softens caked on food that is really hard to scrub off. When it's done, I reuse the vinegar/water concoction. I dipa rag in the mug of vinegar/water then proceed to wipe off the mess.
It makes cleaning really easy and less frustrating. Plus, I feel better that it's natural and there isn't any chemical residue to possibly get in my food while it's cooking.