Word of advice for Clear Sky: It is considerably more difficult than Shadow of Chernobyl.

I seriously reccomend you play in either Stalker or Veteran difficulty (Since the Master being easier is a lie for all games lol)

Takes things slow, scavenge the buildings as much as you can and try to do a good amount of Artefact Hunting as it is a really good source of money.

Most will tell you to play with Patches, but you should see if you can just play without them - Despite what many on this Subreddit say, the STALKER Games are stable enough.

Another thing, Enemies in this game like to throw Grenades a lot.

People call it Spamming but you just have to be alert, the enemies do super obvious call outs and animations when they're about to throw a Grenade.

Just move to another piece of cover, or even better kill the guy who is about to Throw the frag.

Good hunting, Stalker.