Slackbuilds are really nice. Sbopkg lets you download queue files for each program, then automatically install necessary dependencies in the correct order, no matter if they're available as packages or from source. Unfortunately, Slackware is so bare-bones out of the box that there are still pitfalls. For example, LibreOffice depends on avahi. And to successfully install that, you first need to create an avahi user and group, then install avahi, then write an init script that starts the avahi daemon and another one to stop it on shutdown.
-Current is much too active for my personal taste. I run Slackware because I'm a lazy Slacker.
The laziest approach to Slacking today is to install the default full install, then do:

wget https://github.com/sbopkg/sbopkg/releases/download/0.38.2/sbopkg-0.38.2-noarch-1_wsr.tgz    #Download the Slackbuilds helper Sbopkg  
slackpkg install sbopkg-0.38.2-noarch-1_wsr.tgz                                                  #Install it  
sbopkg -r                                                                                        #Sync its local repository to Slackbuilds   
sqg -a                                                                                           #Build queue files (dependency info) for the repository
sbopkg -i flatpak                                                                                #Install Flatpak and its dependencies  
flatpak remote-add --user flathub https://dl.flathub.org/repo/flathub.flatpakrepo                #Add the Flathub repo