LG G6 camera - ways to improve photo quality? I was under the impression that the photos on the g6 were supposed to be fantastic because it had 2 cameras instead of one (depth or something like that?) but I find that the photos just generally suck. Not sure how to explain it. But I know that iPhone photos generally blow mine out of the water. 

Are there any explanations for this? I don't have an SD card (it's coming in the mail) and once I put it in maybe that will change some default settings?
were supposed to be fantastic because it had 2 cameras instead of one 


Having 2 cameras doesn't mean anything, Pixel 2 takes better photos than a "Dual camera" iPhone X


  Are there any explanations for this? 


The hardware isn't good enough. The software post processing isn't good. And the screen on which you look at pictures plays a big role too. A bad iPhone image might look good on Pixel screen but not vice-versa. This Verge Video explains this quite in depth. 


  don't have an SD card (it's coming in the mail) and once I put it in maybe that will change some default settings?


Nope, it won't change anything.

As for answering your original question, yes you can improve your camera to make it a lot better. Easiest way is to install a 3rd party camera app (I recommend Google's Camera port found here). The difficult but sure shot way of improving is to capture images in RAW format and then post process them yourself later on. In a gist, RAW photos will give you unadulterated photos without any of the shitty software processing done by LG. You can then tweak the photos to whatever style you like the most (see it as Instagram filters but on steroids). This is how most professional photographers actually create their stunning images. 

If you want to tweak them on your phone, Snapseed and Lightroom are the best apps. You can look at some introductory tutorial online and its very easy once you get to know what every setting is doing.