Update (February 2015)
It seems that the options that are described in this tutorial have been added to the default game settings. Following this guide is no longer viable in order to further increase your FPS.

Original guide
This is for people who want to increase their in-game FPS. By following these instructions you will completely disable shadows and decrease some graphical reflection settings (which, as far as I know, will be most noticable on stone buildings) in Life is Feudal: Your Own. This will result in a FPS gain on most systems, but results may vary.

These instructions will have you change settings which cannot be changed from the in-game menu. There are still some tweaks left that can be made in-game. Lowering the "Trees Details" and "Object Details" in-game may have a positive effect on your FPS, although not as much as removing the shadows and disabling reflections.