One of the first choices you will make is whether or not to build device support directly into the kernel or as a module. You may choose to disable some options entirely. Though you will not have any performance increases, there are advantages to disabling features that are not required. For one, the compile times will be drastically reduced depending on which subsystem is disabled. For another, the final kernel and installed modules will require less space. On modern hard drives of 40G, 60G, and even 250G, an extra 20M or so is negligible but is significant on embedded or older systems. The disadvantage is that you will not have support for those features until you recompile the kernel. One other thing to keep in mind, as noted in KERNELTRAP.ORG (http://www.kerneltrap.org/node/view/799):
Having unnecessary drivers will make the kernel bigger, and can under some circumstances lead to problems: probing for a nonexistent controller card may confuse your other controllers. –kerneltrap.org
Build any modules you configured with make modules.
Use the command make modules_install to install the kernel modules (even if you did not build any). Make sure that you type the underscore (_). This will install the kernel modules into the directory path.