Any suggestions about forms of backup? I use Acronis True Image...
About the backup types, I would recommend you have
at least one full system image (like
@illumination suggested).
I usually create full system backups like this:
1. Immediately after Windows installation and driver installation.
2. Immediately after Windows has finished installing all important updates.
3. Immediately after installing and configuring essential security software (and maybe some other important applications like web browsers or even 3D modeling/animation software or any such software, since that will save you the re-installation trouble)
Make sure you cleanup your system of junk files with Windows Disk Cleanup or CCleaner (or similar) before you do the backup, so thag you don't backup junk too.
IMPORTANT Make sure you do a test restore immediately after creating each image to make sure it works. If you do not, then you might be taken by surprise in the future if you try to restore your system from one of those system images, and you find out that for some reason they do not work.
As for individual files, I recommend you copy them somewhere safe (e.g. an external HDD or a cloud storage service like
MEGA) and maybe encrypt them using a program like
VeraCrypt.