I used to see mothers with two small children in the supermarket and wonder, "How do they do that?" People now look at me with that same question on their faces, and sometimes on their lips. In case it is on yours, I will explain.
First, we have to leave. This entails making sure everyone has been fed, changed and/or pottied, and dressed in shoes, jacket, and hat. (Actually D2 hardly ever wears shoes, even to church. I'll pretend it's my concern for his proper muscular development and not just laziness.) This must be done in the proper sequence, or a step will have to be repeated again before we go. Half of the steps must be left until the absolute last minute, when they must all be done simultaneously.
Then we must get in the car. I no longer measure the difficulty of a trip by how long we spend driving, but by how many times we get in and out of the car. D2 rides out to the car in his carrier, which he is just barely small enough to still fit in, and just barely light enough for me to still lift. The diaper bag is, hopefully, on my back, and D1 walks on her own volition, holding my hand whenever I can manage a free one. Sometimes she trips and falls, especially while going over the curb.
We arrive at the car, where I try to determine whether it would be better to set D2 out in the elements while I put D1 in the car, or trust to D1's training in standing still with one hand on the car while I put D2 in the car--the answer depending on the inclemency of the weather, the busyness of the parking lot, and which side of the car I happened to go to first.
We drive to the store. There, I must repeat the getting-in-the-car process in reverse, with the added twist that now D2 has to go in the pouch I am wearing, and thus if I get him out first, I have to lift D1 out while D2 gets smashed between us. He doesn't like this. He doesn't like it again when I try to lift D1 into the shopping cart. (I always circle until I can find a parking spot next to an occupied cart return.) Bonus fun if the shopping cart has one of those automatically sticking up plastic flaps, which require you to have three hands: one to hold the plastic flap down, two to maneuver the child. I quickly grow a third hand.
After this, we are home free for awhile. D2 is happy in the pouch, watching the proceedings. D1 is happy riding around the store, commenting on the produce and greeting all and sundry. By the time we are halfway through the store, however, the cart begins to get very heavy and veers dangerously from side to side. (Remember I'm propelling 40 pounds of children and diaper bag on top of a week's groceries for three hearty eaters.) We do our best not to flatten anyone's grandma, while politely answering her exclamations.
We make our way through the checkout line, get everyone out of the cart and into the car, and unload the groceries into the back. We drive home. Here the getting-out-of-the-car procedure is reversed, and I face another conundrum. I dare not leave the children alone in the car--I should not leave them alone together in the house--the food, if left in the car, will spoil--and everyone needs to be fed and changed and/or pottied again, plus outdoor clothing removed. I work out a compromise based on the most urgent needs (usually like this: D1, potty; ultra-perishable food; D2, lunch; somewhat perishable food; D1 and I, lunch; put D1 down for nap; remaining food).
As soon as the last bag of food has made it into the house, I consider myself done for the week. D1 can help me put things away later. I go take a nap.