Yes, a follow up to my leaf blower question. I'd rather move on and
learn from this. I *do* know that 2-cycles require a proper mix of oil
in the fuel, and I *did* read the manual, but I managed to screw it up
for a variety of reasons.

Given that I'm not the only person with a busy life and crazy-ass
distractions, how do YOU try to make sure that you get the right oil
mixture in your yard tools?

US measurements are just the first of many ridiculous parts of the
equation here (sorry, traditionalists). You get a 32-ounce gallon (or
64-ounce two-gallon) container and some other container for the oil and
directions to put (say) 6.4oz (out of 8oz in the container!) in the gas
-- but who has a fluid measure with tenths marks? Not to mention that
the containers themselves are opaque (the cans, at least, by federal
law) and unmarked with fill lines or any such. (One can ensure an even
two gallons via the gas pump, but that supposes a 100% empty container
to start with.) Eyeballing it, which is what I have always done (without
seizing engines in the process, either), just seems risky now.

[In any case, I don't think it was a poor mix on my part, but use of the
wrong container in a rush.]

So, you have to have some gas sitting around for various purposes. You
don't want to run to the Shell every time you need to touch up the
driveway or whatnot. You may need to have different mixes for different
engines (no oil for the 4-cycle mower, 40:1 for the leaf blower, 50:1
for the chain saw, etc.). The containers aren't well designed for this
task. The measuring system is ridiculous. Math is involved. Yet a
mistake seems like it can kill an engine.

Do you mix each one in advance, or add the oil on fueling? What do you
measure with? Do you label and separate the containers? (What do you do
if you label something 40:1 and then forget to mix it once?) What do you
do with leftovers (mixing fresh gasoline with mixed, or the last 1.6oz
of oil)? Is there a visible color change you can get used to in seeing
the fuel (and legal transparent containers to keep it in)? Has some
smartypants invented a device which does the mixing for you, and is
available if you call 1-800-GAS-MSTR in the next fifteen minutes (but
wait, there's more)? Surely somebody has put their brains to this
problem before.

I found one google result for "pre-measured 2-cycle oil" -- the Mantis
products offer a kit with six just-the-right-amount containers. Surely
there's more?