I did a long ride the other day and my feet got soaked from the rain. My shoes are semi waterproof walking through muck and low lying water but heavy rain soaks through the top in minutes. The cleat area is sealed so the water doesn't drain if it gets in. Most rain booties I was able to find online are for cold weather riding. They were either neoprene or a semi/non waterproof spandex. I decided to quickly make some rain booties for an upcoming double century. The back is Velcro and the rest is scrap sil-nylon. Total weight for both is 0.6 oz for a size 11 shoe. They fit my shoes tight enough so they stay put.

do they actually keep your shoes dry or does rain not come in from the top?

The entire rear is Velcro to put it over the shoe. I can easily make it tighter around my ankle. My main priority was to keep most of the water off and get these things finished extremely fast. I probably won't bother to seal the seams. If I wanted total waterproof shoes I would probably look at new shoes.

I'll be interested to hear how they worked. I was going to make something very similar. Something to keep rain falling from above or sliding down my rain pants and being deposited into my shoes.

The commercial ones are similar, and also in that they can't guarantee water proofness either. I used to ride a lot, and we still got wet feet in winter during long hours in the saddle in the rain with the best of covers - we wore them more for warmth, actually. I've even used bread bags as a quick fix on several occasions when on holidays and on a social ride with borrowed gear - works well, but not durable, but shows the point. This being, your idea is sound and should work brilliantly. Good on you!
craig

I tried them out this Saturday and they stayed on my shoes just fine. It rained but not enough for a good waterproof test. I'll see if I can post a pattern if anyone is interested.

not really about the MYOG part but since there's discussion about function...
Borrowing from the hiking, I prefer to use waterproof socks and let my shoes get wet. I use non-breathable, PU-nylon (silnylon would work too) socks with my regular, insulating socks inside. A much better seal, a much better fit and it's no problem to step down and walk, if necessary, which is one of the main issues with booties. Regular strategy about using quick drying shoes so it's not that big of a problem to let them get wet. A solid plastic bag works quite well too but it seems to always break eventually.
Nice item anyway, looks great.

Nice Super Gaiters!
Also check out RBH Designs Vapor Barrier Liner socks. The best $40 I spent on gear this year. I haven't tried them for rain, but for winter biking, xc skiing in slush, etc they are great. For a rain worthy setup I'd try shoe/Grocery bag or 2nd pair RBH sock/wool sock/RBH sock/foot.
Here in CO we don't get much opportunity to test stuff in the rain...

I was thinking of doing the exact same thing, waterproof overshoes are about £30 over here and they're made of heavy breathable fabric, which seems pretty pointless, and have loads of velcro and rubber bits all over them.
Were they easy to make? I've been a bit daunted by getting a good fit so haven't tried making them yet. A pattern would be pretty useful if you have one.
Good work!
Matt