The way I do it.. I use SBOPKG. Take Filezilla for example since I've
actually frequently used it.
When you run sbopkg, first sync.
Go down to search and type in first dependency: libfilezilla
Follow menus to select build and install.
Next do the same for wxGTK3.
Then lastly Filezilla.
Next time you run SBOPKG you check for updates. If it lists filezilla,
wxGTK3 or libfilezilla:
Allow it to add packages to queue.
Unselect Filezilla to allow the others to build/install first.
Then proceed to Filezilla. Always work backwards.
From my personal experience I almost always was updating VirtualBox,
Nvidia drivers, Filezilla and rarely anything else. The first two mostly
if there are Kernel updates.
KEEP A CHANGELOG. This has been incredibly useful for me. I just throw in
the date and time I installed something, why I did, and if it uses non-
default-Slackware packages, I list them. It's easy to search and find
exactly why something is there. Seeing an update in sbopkg for something?
Find out what it uses in the Changelog! :)