Debian way to compile your own version of a package

[Matteo Riva <muradin@gmail.com>]

I would like to recompile Vim with a specific patch, and I'd like to
know what's the recommended way to do so in a Debian system. Should it
be kept separate - like in /usr/local - or should I create a .deb
package with a special version name and replace the official one?

Thanks.