Best way to take screenshots in CS2?

Hey folks, I have a city that I would like to share some screenshots of but whenever I take them, they look like crap. I see others producing beautiful screenshots, and I think it's not just down to hardware.

How do you guys usually take screenshots to get the best results? Do you crank up the graphical settings higher than you would normally be able to play temporarily? Is there a high-res screenshot button somewhere that I'm not aware of? Do you use the in-game screenshot tool or just F12?

Any advice would be much appreciated!