Always A4 printouts for me, but in black-and-white - not wasting colour ink on advertising!
Done at least 24 hours in advance - <mumble> decades in IT has convinced me that printers are sentient, and *know* if you are in a hurry, and so decide to throw a hissy fit.
I used to use an inkjet printer, but found that after a few months of inaction, the printheads had inevitably seized up. So replacement cartridges at ~20 quid a go. So I bought a laser printer for ~120 quid. Came with "starter" toner packs but they were still good for a lot of printouts. Official refills would have been ~400, but found a toner top-up company that could provide chips and toner for ~200 - which will do me for many years. A bit of DIY involved, and laser ink is *very* messy stuff...