There was a video a while back(Set up UT for PUGS or something like that), but that was before UT469 was a thing and a lot of stuff wouldn't really be useful anymore.
b1o would be a good person to ask about tweaks, I tried tweaks when my good PC died and I was using a GT710 for a few weeks(remove shock beam, hit effects ect to help with stuttering FPS when shooting shockrifles), it's more complicated because some servers/communities allow and others will ban you for using them, it's also a personal preference thing.
OpenGL for 469D has a much more user friendly way of changing advanced graphic settings, so you don't have to mess around changing ini files as much, for example you can apply MSAA with a drop down list, change gamma values, onexblending settings and others like the traditional UT settings menu, no idea when it's going to be released though.