Backing up things is always important and while it can be done manually here is a neat way to organize folders/files and transform them to become iso images.
First you need to install a program called genisoimage. (Debian family: apt-get genisoimage / Arch: pacman -S genisoimage / Gentoo: emerge genisoimage)
Once you have installed genisoimage open a terminal and type: genisoimage -o file.iso File
In the command -o file.iso is the output file, which comes as a result once the command is done. The final part: File is a name of the folder, which gets included to the resulting iso image. You can include multiple folders and files to the iso image by just listing them like the folder File on the above. Do note that you might need to give a full path to a folder File and others – if they do not reside in the same location that you are currently in. An example: if the folder is in your home directory and you navigate your terminal client to your home directory then you can use the command above as it is. If you want to create an iso from the folders/files, which are not in your current location then you need to give full paths pointing to them.