I am using Microfiber cleaning cloth. Same kind I'm using with my DSLR Camera and lenses, you do not need much pressure to clean screen. If put in the pocket, it will crack only if you put some pressure on it (bend it, against keys, etc.) Normal cleaning is not a problem.

 

Agreed with the 'keys' comment.
I always make sure that my phone is the only thing it that pocket (front pants pocket). No scratches, no extra stress when I sit down.

 

i wouldnt worry about scratching it. You seem intelligent anough that if you were to see a bunch of sand on the screen you wouldnt GRIND it off with a towel. I use my shift if i have to.. i just wet the screen slightly and wipe. Also man get a screen protect if you dont have one. I have a screen protector and i bought the OtterBox Defender which has a built in screen protector and i have had zero issues. i actually press decently hard what i clean it.

the people that are cracking screens are like the guy siad above. he is putting it in his pocket sitting on it which bends it, keys bending across the screen or grinding on it. i wouldnt worry about it at all. if you put it in your pocket get a good case liek the one i am using. If you clean it, you know things that scratch, rocks, pebbles, bambam, dino. You will be fine. The screen isnt a cheap piece of junk, but it isnt the razor's gorilla glass either.

hope this helped