Arch Linux provides for several methods of kernel compilation.
Choose one of the following:
1. Custom kernel the traditional way
This method involves manually downloading a source tarball, building in your home directory as normal user, and then installing as root.
2. Custom kernel using ABS.
This method allows for custom kernel compilation using the Arch Build System, or ABS. It provides a PKGBUILD file to modify for your needs.
A small minority of Arch users prefer the traditional way, however using ABS is helpful for automating certain tasks. The choice is yours, neither way is inherently better than the other.
3. Kernel Compilation with ABS will allow you to use ABS to build the provided -ARCH kernel.