I make it a point to steal a little something every time I'm forced to use these.

Big box hardware stores appear to have zero people to check you out anymore, so they all give me something every time I shop.

Pro tip: they won't bother if you dont steal anything expensive. Additionally, there are cameras in the ceiling that are working with the register to see what is in the cart and determine if you have scanned everything. Buy a cardboard box (cheapest thing that works). Lay it over your cart. Put stuff under it and now the system cant see your cart to determine if you stole something. A GFCI outlet or two never seem to go noticed.

If the self checkout spazzes put and needs me to get an assistant, that's the last thing I scan at the checkout. Lady comes over, overrides the fail, I say thank you, pay for the stuff while she's standing there, and put it back in the trolley with the stuff I didn't scan yet. You see, I was so frazzled and confused by the disruption that I forgot I still had things to scan. Plausible deniability, I never hid anything, it was all out in the open, and the lady was just standing there. If she mentions it, then I can just resume scanning those items and pay for them too. This has not happened in several dozen grocery trips.

I just get so anxious and confused so easily!