For mirrors and glass, Windex works for me. Spritz it straight into the glass and use a cloth or paper towel to rub over until clean. You will need to have a light pressure with the cloth to rub it over and remove the residues. However, this is just for regular dirt and dust. If you have shower glass with soap scum, you will need to use something a bit abrasive like Jif or Gumption to get it back to clean. After that can be maintained with a squeegee every time you shower, but frankly I can’t be bothered with that. Just clean it regularly with jif.

Try warm water and a small squirt of dishwashing liquid in a bucket and a microfibre cloth or chamois to dry.

I've always used a squeegee and dishwashing liquid and water in a spray bottle, then blotted off any remaining dribbles with an old handtowel. The residual stains on the mirror may be behind the glass and if so cannot be removed. Its called mirror cancer. Only way to remove those is to replace the mirror. Happens when water/moisture gets into the silvery backing of the mirror. Worth trying with dishwashing spray as above and if that doesn't fix it it's probably permanent. Don't waste your time with windex or similar.

Paper towels work best. Spray with windex (or similar glass cleaner) and wipe in a circular motion. You can use a squeegee but that can leave streaks and doesn't remove stains very well If there are soap scum stains, I use a bathroom spray and leave it for like 20-30 minutes. Make sure you've got the fan on and doors open (window too if that's available). Wipe with a cloth, then squeegee.

vinegar and microfibre. buff buff buff