IMHO, if you make it easy for distribution packagers, they will come. That means:
- State the
URL of the project clearly.
- Have the version number of the project in a file in a way that's easy to parse (e.g. a Makefile variable, a file version.h or similar) and
keep it up to date.
- Have a file called LICENSE[.txt] in the sources, that has the
license text (preferably a standard OSS license).
- For each release provide a tarball or zip that includes the
version number in the file name and stays available at the same URL forever.
- Have a README or INSTALL file in the sources that clearly lists the
steps to compile and install the software. Document any configure or make flags for compiling in special features or libraries. Document
all dependencies.
- Avoid including third-party libraries in your sources and/or linking them statically. If you must do so so, provide a way to compile your project with already installed versions of third-party libraries and, preferably, linking them dynamically.
- Check that your software compiles with modern GCC versions (i.e. at the moment GCC 6 and 7).
- Make it easy to find a way to provide feedback, support requests or bug reports for your software, i.e. state a contact address or a bug tracker URL prominently on your project's web site.
I could go on, but I think these are the most important things. If you want to create packages for some distributions yourself, I suggest starting with creating a PKGBUILD file for the Arch Linux User Repository, since they are very easy to write.
https://wiki.archlinux.org/index.php/Creating_packages
Chris