One way to create a good enough .config file is to install kw and run:
$ kw configm --fetch --optimize
The command might ask if you want to overwrite the existing .config file. It might also ask to define some other settings which, in general, will work when choosing the default option. Read more about the command at the kw configm documentation.
This is a micro-post about the Linux Kernel compilation process, its main purpose is to highlight and redirect to valuable resources.