I've recently learned that if I use the "Something-else" install option, and install Ubuntu 18.04 over my existing 16.04, it will keep track of my installed packages and, versions permitting, reinstall them when the installation is completed.
When I've tried to use do-release-upgrade, however, I've been informed that the upgrader needs to remove all of my non-Ubuntu repositories and installed packages to proceed. While I can understand why this is needed, it's very inconvenient because it greatly increases the time I need to spend on the process.
Is the "reinstall packages" support present in the upgrader as well as the "something-else" install? And if it is, does that also include third-part repositories and packages like current versions of Wine, SeaMonkey browser suite, or Skype?
many things changed in 18.04 LTS and my modest recommendation after several upgrades from 16.04 to 18.04 is: 1.) Install Ubuntu 18.04.3 LTS (latest version !) over the existing 16.04, and 2.) Make tasks explained in https://itsfoss.com/things-to-do-after-installing-ubuntu-18-04/. 3.) In case you need still some additional other software, download from Ubuntu Application Centre the programs which Ubuntu 18.04 supports. Keep in mind next Ubuntu LTS (version 20.04) will be launched next year spring.
(Before any installation remember to make safety copy of all your works somewhere.)
According to my experience tasks 1.) and 2.) will time your time about 1,5h.