I like LXQt and use Lubuntu.  I'm trying out Debian LXQt because of...
snap issues.  So here's the Debian LXQt edition of my previous Lubuntu
  
productivity software
  to install and  migration
  
notes. 
  TL;DR...
  
  # for building some kernel modules
  
  sudo apt-get install build-essential dkms linux-headers-$(uname -r)
  
  
  # enable contrib and non-free repos
  
  sudo sed -ri 's/^(deb.*main)$/\1 contrib non-free/' /etc/apt/sources.list
  sudo apt-get update
  sudo apt-get upgrade
# productivity software I like (note nomacs is in Debian unstable repository)
sudo apt-get install chrony file-roller xournal evince nomacs
  graphicsmagick ghostwriter emacs gimp gimp-plugin-registry gimp-gmic
  default-jdk gcc make ttf-mscorefonts-installer ruby vlc  gedit 
  # enable libsecret for git
  
sudo make --directory=/usr/share/doc/git/contrib/credential/libsecret
git
  config --global credential.helper
  /usr/share/doc/git/contrib/credential/libsecret/git-credential-libsecret
# because where I am, it's hard to contact a time server except Apple's...
echo 'server time.apple.com iburst' >> /etc/chrony/chrony.conf
# make an icon for GraphicsMagic
cat > ~/.local/share/applications/GraphicsMagic\ display.desktop << EOM
[Desktop Entry]
Encoding=UTF-8
Name=GraphicsMagick display
Comment=GraphicsMagick display
Exec=/usr/bin/gm display %F
Icon=lximage-qt
Categories=Graphics;Viewer;RasterGraphics;2DGraphics;Photography;
Type=Application
MimeType=image/jpeg
Terminal=false
EOM
  
  
    curl "https://awscli.amazonaws.com/awscli-exe-linux-x86_64.zip" -o
    "awscliv2.zip"
  unzip awscliv2.zip
  sudo ./aws/install: 
ttf-mscorefonts-installer might require user interaction to
install, so don't walk away from it overnight thinking everything will be done
by morning.
Then install 
by hand VS Code, Chrome, Netbeans, and LibreOffice
dictionaries and plugins etc.
Software to Download and Install by Hand
The default package manager using the default Debian software sources (testing channel) are pretty
good at keeping up with the versions.  I like doing that most of the time
to reduce on maintenance.
Some things are worth the manual install though.
1.
LibreOffice needs some extensions, dictionaries, and settings:
  - 
    an extension I rely on a lot: 
    MultiFormatSave.  Let's you save a document to multiple formats at the same time, great
    for archival compatibility.
 
 
- it needs a dictionary for spell checking!  For English,
these
    dictionaries from LibreOffice are good.
 
 
 
- this setting is essential to
    prevent previews of recent documents on the start screen, which is quite a privacy blunder:
  
    - 
      Tools menu > Options > LibreOffice > Advanced > Open Expert
      Configuration > Search for RecentDocsThumbnail property >
      toggle to false.
    
 
 
2. 
Google Chrome is
self-updating.  I prefer Firefox, which is installed by default, but sometimes you need Chrome.
3.
Apache NetBeans.  This requires as a dependency the Java JDK at least version 8.
  - 
    So use muon to install the default-jdk because the default is version
    11, which works fine so far.
 
 
- 
    And get the
    "Maven Remote Search" plugin
    before Netbeans starts downloading and extracting the maven index that's
    apparently more than 1 GB in size (froze my computer since I have very
    little disk space...).
  
 
 
4. 
VS Code.
Screen Saver Lock Screen Madness
It's madness, there are at least 3 places to set the screen saver / lock screen / sleep
settings:
  - Preferences > LXQt Settings > Session Settings
- Preferences > LXQt Settings > Power Management
- Preferences > Screensaver
They seem to interact with each other, and each has slightly different settings and
uses.
My default Screensaver sometimes ran the CPU real hot, so maybe set that to
something less energy intensive first.  I used 
Deco with settings reducing the
framerate.
I'd suggest using each tool for orthogonal tasks:
- use Screensaver purely for setting the screensaver and when it
turns on.
 
 
- Set when the screen locks using Power Management (Idle tab).
 
 
- Use the Session Settings to set whether the screen locks before suspending the
OS (I think it defaults to locking after suspending).
 
For reasons, I like file-roller.  So just install file-roller via apt-get.
The default file explorer PCManFM-Qt has a preferences
option to integrate with file-roller instead as well for ease of use.
Explanation of certain software choices
Basic graphics editing
The default graphics viewer LXImage is actually a bit of a pain to use,
especially coming from Mac Preview, which really has a great mix of UI, UX, and
editing features for graphics 
and PDFs...
There's no equivalent to Apple's Preview, but for graphic files,
nomacs Image Lounge is
pretty good.  nomacs has a UI UX reminiscent of Preview, and has some basic
graphics editing features too. 
 
Little more graphics editing features
The default graphics viewer LXImage has some annotation tools, I guess, but
nothing more.  nomacs has some more graphics editing features, but I sure
miss the Mac Preview tool.
Anyway, ImageMagick or the more updated 
GraphicsMagick fork is quite
useful (but beware it has a very... historic?... dated?... GUI).  It can be
installed via apt-get, but it doesn't seem to install a
default app launcher icon --- well, it's meant to be used from the terminal, but
I like to deal with the GUI.
So I added a blank file to 
~/.local/share/applications called "
GraphicsMagic display.desktop"
with the following text saved to it:
  [Desktop Entry]
Encoding=UTF-8
Name=GraphicsMagick display
Comment=GraphicsMagick
  display
Exec=/usr/bin/gm display %F
Icon=lximage-qt
Categories=Graphics;Viewer;RasterGraphics;2DGraphics;Photography;
Type=Application
MimeType=image/jpeg
Terminal=false
Now you can use it like LXImage (in fact, it uses the LXImage icon because, why
not?).
If I need more intensive graphics editing, I'll use GIMP.
Time Clock Auto Update Synchronization Problem
Debian looks to use 
timedatectl by  default for setting time,
including synchronization via NTP Network Time Protocol.  It doesn't allow me to force a sync though.
You could instead use 
chrony.
It lets you do things like 
chronyc sources to see the currently
available and selected time sources.  Perhaps your network is blocking NTP
updates?
Or 
chronyc sourcestats to see your clock's time offset from the
various NTP sources.
You could do a single time offset check, without setting the time:
sudo chronyd -Q
Or manually force a time synchronization with: 
sudo chronyd -q
Oh, and I like to add to /etc/chrony/chrony.conf  :
  server time.apple.com iburst because where I am it's hard to get to a
time server except Apple's.
  
Microsoft Fonts
Install 
ttf-mscorefonts-installer.  Some
instructions
for this but it's straightforward from the package manager.  Just use
sudo apt install ttf-mscorefonts-installer.
 
Backup
For file backup,
restic looks great.  Some people like 
borg.
Remember Git passwords securely
Git is great. 
Remember Git passwords securely
is even better, but requires manual install though.
Misc
keynav  ---  Didn't have it in Lubuntu, but it exists for Debian!!!!
skippy-xd  --- It hasn't been updated and doesn't work anymore for Lubuntu (OpenBox, LXQt).  Debian LXQt uses Xfwm though, so somewhat similar functionality is already built in!