The first morning of potty training sets the tone for the whole week. Our first time, we started with no plan. The potty was upstairs, the wipes were in the car and the spare pants were still in the dryer. By lunch, we were frazzled and our toddler could feel it.

By our third child, we had a routine. The night before day one, we walked through the house with a checklist and set everything up. The next morning was calm. When an accident happened, everything we needed was right there.

Here's that checklist, room by room, with the reasons behind each item and what to do when something doesn't go to plan.

On day one, your main job is to watch your child and get them to the potty in time. Every second you spend hunting for wipes or running upstairs for clean pants is a second you're not watching. A good setup lets you stay calm and close by, and calm parents make for calmer kids.

It also helps your child. When the potty is always in the same spot and the routine is the same every time, they learn faster.

This is home base. Make it easy for your child to do as much as possible on their own.

• Potty chair or toilet seat insert. Pick one and stick with it for the first week.
• Step stool. For climbing up and for resting feet while sitting. Feet flat on a stool makes pooping easier for a lot of kids.
• Wipes and toilet paper within reach. Put them where your child can grab them without standing up.
• A small basket of books. Two or three short potty books help kids sit for a minute or two.
• Hand soap and a low towel. Washing hands is part of the routine from day one.
• Sticker chart and stickers. Tape the chart to the door at your child's eye level.
• Night light. Helpful for early mornings and dim hallways.

Tip: Do a "practice run" the night before. Let your child walk into the bathroom, climb up, sit (clothes on is fine), "wipe," flush and wash. It makes the real thing feel familiar.

This is where you'll spend most of day one. Many families also put a second potty chair here for the first few days so it's never far away.

• Second potty chair (optional). Put it on a mat or towel near where your child plays.
• Accident kit. A small bin with paper towels, a spray cleaner, a few old towels, a plastic bag and one change of clothes.
• Waterproof cover for the couch. A shower curtain liner under a blanket works fine.
• Easy-off clothes ready. Elastic-waist pants or shorts. Skip overalls, belts, onesies and tights for now.
• Quiet activities on hand. Puzzles, play dough, coloring and a few new library books keep everyone close to the potty.

Drinks help create lots of chances to practice. Snacks keep everyone happy at home all day.

• Water and a favorite cup. More drinks mean more practice. Don't overdo it, just offer regularly.
• Easy snacks prepped. Cut fruit, crackers, cheese and veggies ready to grab.
• Simple meals planned. Leftovers, freezer meals or sandwiches. Day one is not the day to cook something new.
• Fiber-friendly foods. Fruits, veggies and whole grains help keep poops soft and easier to pass.

You'll do more small loads than you expect.

• Laundry caught up. Start the day with empty hampers.
• 10 to 15 pairs of underwear. Washed and stacked where you can reach them.
• Extra pants and socks. Accidents often soak socks too.
• A lidded bin or wet bag. For wet clothes until you run a load.
• Stain spray. Keep it next to the washer.

You'll probably stay home for the first few days, but have this ready for when you do go out.

• Travel potty or folding seat insert.
• Two full changes of clothes, including socks.
• Wipes, wet bag and plastic bags.
• Car seat liner or a towel under your child.

The most important setup item is you. A calm, rested parent with a plan is the best potty training tool there is.

• Calendar cleared for the first two or three days.
• Words agreed on. Pick the words you'll use ("pee," "poop," "potty") and the phrase for accidents, like "Oops, pee goes in the potty."
• Potty times written down. After waking, after meals, before and after naps, before bath and before bed.
• A cue tracker. A simple sheet where you jot down when your child went and any signs you noticed before. Patterns show up by day two.
• Caregivers in the loop. Partner, grandparents and babysitters know the plan and the words.
• A good night's sleep. Easier said than done, but worth trying.

This is roughly what our first day looked like. Adjust it for your family.

• Wake up: Straight to the potty. Big cheer for sitting.
• Breakfast: Drink with breakfast, then potty after eating.
• Morning play: Offer the potty every 20 to 30 minutes. Watch for wiggles, squats or going quiet.
• Lunch: Potty before and after.
• Nap: Potty right before. Diaper or training pants for the nap itself is fine.
• After nap: Potty right away.
• Afternoon: Same as the morning. Maybe a short walk if things are going well.
• Dinner, bath, bed: Potty after dinner and right before bed.

Even with everything in place, day one can be bumpy. That's normal.

If there are lots of accidents: Look at your cue tracker. You may need to offer the potty more often, or watch more closely in the 10 minutes after drinks and meals.

If your child won't sit: Keep it short and fun. Read a book on the potty, or let a favorite toy "sit" first. Never hold them there.

If you're feeling overwhelmed: Take a breath and take a break. Put on a show, have a snack, and reset. Your child will pick up on your calm.

If your child seems uncomfortable or strains to poop: Keep things relaxed and check in with your pediatrician if it continues.

• Buying too few pairs of underwear. We ran out by noon on our first try. Ten is the minimum; fifteen is better.
• Putting the potty in a far-off bathroom. If it takes your child 30 seconds to get there, many trips will end in an accident. Keep it close for the first days.
• Switching potties halfway through. Changing from a chair to a seat insert on day two confused our toddler. Save the switch for later.
• Planning a big meal. Cooking something new on day one meant one of us had our back turned at the worst moments.
• Forgetting the car. On our first short outing, we had no towel on the car seat. Lesson learned.
• Not telling the grandparents. They visited on day two and offered a diaper "just in case." A quick text the night before would have saved a lot of confusion.

We printed our checklist and taped it to the fridge the night before. Checking things off felt good, and the next morning we didn't have to think. Everything was where it needed to be.

If you want a fuller version, The Prep-First Potty Plan includes the whole prep week, the day-by-day training plan and seven printables that go with it.