If for some reason the default font looks like Times New Roman, even thought the default fron is set to Liberation Sans, you might have to re-set the default font:

Select Tools > Options > LibreOffice Writer > Basic Fonts (Western), and change temporarily to another font and press Ok, perhaps close the program. Open and change back to Liberation Sans and press Ok, the default font should now truly be Liberation Sans.

Setting up a Linux installation can be done in many different ways, but preserving your settings and bookmarks is nice, so you don't have to redo them after a re-installation. This set-up uses another partition (in the example, called "documents") to store your photos, documents, settings for installed programs and your mail program, and connecting to them via symlinks. This way you can re-install Ubuntu and be up and running fairly fast.

Sometimes, the font size on a web site is too small, for example at https://www.retsinformation.dk/ where the font-size is 11.2 pixel. You can override the text size locally, via the userContent.css file.

Also, highlighting links can be useful, to allow tabbing between them.

Add a file named userContent.css file inside the Firefox profile folder (you might have to create it) at ~/.mozilla/firefox/ID_STRING.default/chrome/userContent.css

Then add this:

If you need to resize a lot of images, doing it manually in Gimp is an option, but can take a long time.

In stead, you could do it from the command line, with the mogrify tool, which is included in imagemagick.

Install it like this:

$ sudo apt install imagemagick

Use it like this, which creates a folder for the smaller files, and then resize all PNG images to a maximum width of 700 pixels, putting the resulting smaller files in the path/to/image/folder/resized folder:

Ubuntu 18.04 comes with a lot of variations of English, which can clutter the spellchecker in Thunderbird and Firefox.

A quick way of removing some of the variations of English, the safest method is uninstalling the unneeded language packages.

In my case, I had these in my /usr/share/hunspell folder:

da_DK.aff
da_DK.dic
en_AU.aff
en_AU.dic
en_CA.aff
en_CA.dic
en_GB.aff
en_GB.dic
en_US.aff
en_US.dic
en_ZA.aff
en_ZA.dic

To uninstall the unneeded packages, only keeping Danish and US English:

Electrum is a light weight Bitcoin wallet. There are many advantages of using a Desktop wallet, as opposed to keeping your digital currency on an exchange, where you have less control. Another, and possibly safer solution, would be using a hardware wallet.

One of the big advantages of Electrum is that you don't have to download the entire blockchain, so you can start using it right away.

If your Ubuntu installation sometimes drops into a black screen showing something like /dev/sda1: clean, 227147/30269440 files, 3330843/121068288 blocks, try to get get back to your installation by pressing Alt+F2.

You might see a password prompt with this text:

Authentication Required
Authentication is required to update SMART data from Samsung SSD ...

Verifying yourself should fix this.

Pyrenamer doesn't exist for Ubuntu 18.04, but GPRename is a similar GUI batch renamer app from the default Ubuntu repositories. To quickly open a program in Ubuntu, you can press the Super (Windows) key and start typing, but GPRename isn't added after installing it:

sudo apt install gprename

To add the GPRename shortcut to Activities search in Ubuntu 18.04, create a file called gprename.desktop with this content:

If you have switched graphic card driver from Nvidia to Nouveau in Ubuntu, you might get this message after boot, where it just hangs:

/dev/sda1: clean, ***/**** files, *****/**** blocks

Solution:
Click ESC during boot
Select Ubuntu with Linux ... (recovery mode)
Select Resume normal boot
You should be able to log in, switch back to Nvidia end reboot

You can reduce the size of a video by reducing the resolution with the ffmpeg program.

Install:

sudo apt install ffmpeg

Lower the quality, for smaller files

Add for example -crf 26 to reduce the quality, where 23 is the default, 0 is lossless and 51 is worst quality.

This simple example, reduces the quality a bit with the -crf 26 parameter, while simply copying the sound: