Questions about textures
Sup.
1). How many (in general) you use textures for your game environment and what type of texture it is ( atlas, tiling, trim )?
2). Is it normal to make your tiling texture into one image or better combine it into atlas of tiling textures ( is it possible )?
3). For what you use tiling textures, trim sheets, atlasses?
4). How you texturing your game environment? What technique you use and etc.?
5). Is many draw calls so bad or it's not so bad?
The questions may sound very stupid... so am i 
But i wanna clearly understand how, what, why environment texturing works.
Replies
What i would do is open up some free projects/games that have editor access and take a look at those. There are a few SDKs or mod kits on epics store and you basically get a semi-functional game with an editor. Depending on the game type you will see that some use more tileable textures, others rely too much on unique textures and so on. I havent seen atlases used lately on anything but fx and foliage, but they were pretty popular some time ago.
Nowadays, apart for the odd compression system or some atlases in form of volume textures, most companies rely on fancy streaming systems like virtual textures that allow them to use insane amounts of textures at stupid resolutions.
The question about drawcalls pops up now and then and its still the same answer: more dc means more time to render a frame. There's no working around that.
There was a map made some time ago for UDK that used only one texture. That was impressive but i dont think these kind of self imposed limitations have any value except bragging rights. We already work with limitations set by the current hardware, platform, OS, API, etc. So if you have metrics, use them, if not, whatever works.
PS: i dont work or have ever worked in a studio but am aware of current practices in indie and AAA studios.