Cheap components
I only buy equipment from large branded companies with a proven track record of support and maintenance capabilty.
Cheap IT breaks and is false economy.
An example of this is hearing a bloke saying he bought 2 cheap inkjet printers a year because he used them so much they wore out that fast, whereas he should have buying a substantial laserjet with warranty. False economy.
Similarly how many people use tat model hubs, cheap mice, knock off PCs, home brand displays, special offer wifi repeaters, cables from asda, unbranded SD cards, only to have frequent 'IT issues'.
Cutting corners does not mean you will always end up with tat, and buying more expensive gear does not guarantee reliability - but is sure as hell stacks the odds in your favour.
And invest in resilience and redundancy. Have a plan B - like knowing of a local printers who can run off copies from an email or USB drive.