I do have tweaks. I install the shader 3.0 mod. I reduce autogen density in the CFG to 1800 for buildings and trees, which is more than sufficient for me. I also have the TreeX tree modification and I have REX 2.0, which for me brings textures that are not only better quality, but they also up the FPS a little. I then run my cfg through bojote's online tool and then manually add 4096 back in for the maximum texture size, or whatever it is called. That's pretty much it, as well as keeping my computer clean and tidy, no antivirus running, that kind of thing.

Excluding FSX folders from your Anti virus is indeed a good idea but over and above that there is little solid evidence that shutting down services and apps prior to running FSX will provide anything more than a placebo effect. Check out this thread over at Aerosoft for example. Windows memory management has come a long way since XP...