It is impossible to avoid the fact that rain is a problem when cycling. Personally, I think the worst of all is getting wet on my feet. Walking around in wet shoes one day at work is not nice. Rubber boots in the pack on the bike ride feel bulky. Therefore, I was happy when I got a pair of rain covers for shoes from my wife.
We sell them in the web shop, so you should read this with critical eyes, but it was love at first sight. Because they are made of soft polyester-coated vinyl, they are easy to fold and carry in your backpack. Even for an impractical person like me, it is easy to attach them using Velcro. They not only cover the foot but go all the way up to the knee like a boot. If you combine them with a rain poncho, you have good rain protection for the whole body. I might not have them at the Nobel party, but they actually look pretty nice.
The combination of being easy to carry, easy to fasten and effective against rain makes them a favorite.