I don't have a post ride bike care routine. I just roll my bike into the unheated garage and let it drip away.

Once every one or two months, on some weekend when it is raining less than usual, I spray the bike with Simple Green, then blast it with a pressure washer while avoiding the bearings, followed by more dripping. The next day I apply Chain-L, spray WD-40 in the frame vent holes, drip Tri-Flow on the brake and derailleur pivots, and then ignore the bike for another couple months :-)

Once a year, during the spring or summer, I usually spend a couple hours going over the bike more carefully. I check adjustments, check wheel true, re-grease/oil everything, put a drop of oil in each spoke eyelet, and do a more careful cleaning with rags instead of a pressure washer.

I know that sounds slovenly but this is my daily commute bike, so if my cleanliness standards were higher, during the winter I wouldn't have time to do anything but clean the commuter bike! After all, I have other bikes to primp and pamper.

I also haven't done anything special to prepare it for rainy commuter duty, other than fit good fenders. Bikes are mostly aluminum which doesn't rust, the main steel part (frame) is painted, other steel bits are mostly chromed, all in all they seem pretty weather tolerant. The bikes I've seen that are significantly rusted were either left sitting outside in the rain all the time, or were on trainers and got drenched with salty sweat.

Recently I did put together a bike that will be sitting in the rain most days, my son's high school bike. I asked here and got various tips for rain-proofing a bike, and have already done some of them. I stretched a section of inner tube around the lower headset races. I also put grease where the headset locknut and stem meet, and put a rubber grommet over that. I'm going to put extra grease at the seat lug/seatpost junction and cover that with a skirt of fat tire innertube zip-tied around the post. I'm also going to put some greased felt or foam "donuts" over the bearings at bottom bracket and hubs (FBinNY's suggestion). I will spray Framesaver in the frame tubes. And the bike will go out and do battle.

That could be overkill. My son's middle school bike sat in the rain, locked to the school's racks, most school days for three years, and it still looks good, and works fine. A couple of steel bolts are slightly rusty, those could be wirebrushed shiny in five minutes.