Before I start I'll preface this entry with the fact that under Australian Copyright Law you are legally allowed to backup and restore your personally owned / licensed software for the purpose of backup and recovery for those and only those said items. This may not be applicable in your country!
The trouble with old hardware is that it fails and some parts fail more quickly than others. On one of my Amiga's I have already lost a hard drive and the kernel eprom as well. This can be a real nightmare if you don't have a backup (I didn't so I had to buy new legal ones), so just like your photos, documents, software etc etc you should back them up!
CFIDE Backup
If like me you are using modern Compact Flash (CFIDE) drives, it's really easy to back them up. You will need a Memory Card reader that supports Compact Flash and some good imaging software. Take your image and store it somewhere safe. I keep one on my backup drive and one on a spare CF card.
Things you will need.
1) Disk Imager : https://sourceforge.net/projects/win32diskimager/
2) Generic Card reader : https://www.officeworks.com.au/shop/officeworks/c/technology/hard-drives-data-storage/card-readers
3) Spare CF cards : I'm just using 4GB cards.
Kernel ROM Backup
Backing up your Kernel ROM is also easy but you'll need more hardware. You need to remember to backup all of your ROM's as each model Amiga will have a slightly different one. You will also need some spare EPROMS.
Most Amigas use 27C400 EPROM's, the A1200 apparently uses a 27C800 EPROM's. It's a good idea to get a few and just put them away for a rainy day. I also have a licensed multi-ROM that uses a 27C800 so I can have two ROM's on it and switch between them, it was pricey but well worth it.
Mostly the EPROM's available are UV erasable with little windows on them. There are also some more modern EEPROM's about but none that I've seen in DIP format.
Things you will need.
1) UV Eraser : so you can erase them when you make a mistake or if they have stuff on them still.
2) Programmer : I have a GQ-4x4 with the required 16-Bit add-on board.
3) EPROMS : 27C400 for most Amigas and 27C800 for A1200's and ROM switchers
A special note: If you are backing up a 27C800 multi ROM remove the chip from the switcher and back it up as a 27C800, don't try to back it up in the switcher!