I can’t sew to save my life, but I do have a supply of workshop dust masks.
I wouldn’t expect them to provide any real antiviral protection to the wearer, but would they be of similar utility to a home-made surgical mask from a reducing-the-risk-of-infecting-others POV?
That’s my understanding, yes. And if you can put a layer of nylon across it, that would really up the protective nature. I’m sure you’ve got pantyhose you’re not using, right? 
Yes, because the world we thought we were living on is not the world we are actually living on, nor are we in the same quadrant of Laniakea that we thought we were in, nor the timeline.
Reversible, maybe?
(And suddenly I have nostalgia for the reversible Spring “Rain-n-Shine” coat I had in sixth or seventh grade…solid on one side, flowers on the other. It was the 60’s, yeah.)
Yes, you’re right, it is! But technically the tikis are the ‘right’ side: she made a bunch, all with the tikis on one side and various other fabrics she had on hand for the other side.
It is a lovely mask!
For example, don’t be like the guy I have just dealt with whose mask – which looked to be commercially made – had great big gaps at the sides.
Seriously, it just needs to fit close on all sides. This isn’t rocket science. If you put it on with clean hands, you can adjust it so it fits properly.
I am currently on mask V2.1: 2-pieces, curved style with elastic ears and a twist tie nose wire. I’m pretty proud of the construction - fully enclosed seams - and they would be reversible if not for the nose wire channels. The birb fabric ran out, so I cannibalized a truly hideous apron that I never wore. The resulting fabric was enough to make 6 masks (most were the fan fabric on the outside and geisha on the inside, but I wanted to make a “manly” one). I kept one for myself and husband, and sent two to each of my grandmothers across the country. We’re good for a while!
(I accidentally posted this as a reply to another person, not to the thread - boo!)
This looks good. And has some research to explain it.
PopSci:
links to:
https://pubs.acs.org/doi/10.1021/acsnano.0c03252
And colour me surprised as to a double-layer mask made out of cotton and chiffon (90% polyester & 10% Spandex) was that efficient.
For further info on the materials used check the supplemental material.
I, for one, am still wearing a paper face mask given to me when I was at my local practitioner a while a go. Will probably buy several (so I can swap every other day) from the spouse of a co-worker who owns a small shop and now also makes masks (which helps, since business is not exactly good at the moment).
Well, it isn’t pretty, but I managed to put together something that seems to fit well over the nose (using an aluminium foil nosepiece), goes under my chin and past my ears on the side (which should help minimize side leakage, because air would literally have to reverse course and flow backwards). I could not feel air coming over the top or sides, even when trying to breathe hard.
In other words, it should do for social distanced grocery shopping… or at least as much as people let you social distance in the grocery store. It’s a double-layer from an old flannelette shirt. It’s better (though perhaps not too much better) than nothing. I literally intend to wear it long enough to buy groceries and then get home and wash it. And then not leave for two weeks.
Ok, so I had a go at one of these - and despite the instructions being perfectly clear, I still managed to mess it up. Oh, well, that’s why you make a toile first right?
I now know what I did wrong on this one and can make another - where I will no doubt make a different mistake. 
More generally relevant, I can say that if you can manage to actually read and follow the instructions, they are clear and do produce a wearable mask without a lot of fiddly cutting or anything beyond sewing in a straight line.
It could even be hand sewn without taking too long.
My SO just ordered some of these for herself:
We’ve been sewing masks for over a month using the freesewing.org pattern. Use old thick t-shirts and they are pretty effective at covering your breathing ports.
Getting elastic has been a problem. I’ll share my method: buy 1.5" or 2" wide elastic and slice it down the middle. It holds up well in the wash, tho I’d recommend hand washing, ironing and hanging out on a clothes line in full sunlight. Also fun to use parts of the graphics on the outside. Plus they are reversible (just use one side at a time until you wash it ok?)
This is an ingenious design:
