Seasonal Clothing Switch
At all times, I keep a small box for each child in the back of the closet. We call these their "too-small" boxes. I have 3 kids sharing one very small closet that is less than the size of a shower stall. 3 medium sized diaper boxes fit across the back of the closet. Whenever something doesn't fit right or a random out of season item is found, it goes into the child's designated box. The 3 and 5 year olds know which box is theirs and when they ask me about an item that doesn't fit right, they know which box I am referring to when I send them to the closet to put the offending item in their "too-small" box. I suppose I could even have them all share a single large "too-small box" but I like having things partially sorted for me by gender and relative size when I get around to going through them, and it's easier to line just the back wall of the closet with 3 small boxes than to have a giant box in there taking up the whole floor, so I have a box for each kid.
The kids' room closet has 2 bars. It has the standard bar right under the shelf that most closets have, and then we have purchased a second bar that is about 3 feet long and hangs by hooks from the first bar, putting it at about halfway between the floor and the first bar. The hangable good clothing goes on the top bar where only Mommy can reach it. The hangable play clothes go on the bottom bar and the 5 year old is responsible for keeping her own play clothes hung up when not in use or dirty.
A good idea I was reading about for if you have more than a couple kids of the same gender with no more than a year or 2 between each and the next, is to have one large box per person. When a kid outgrows something, it gets put into the next-younger same-gendered sibling's box, regardless of season. Then when that kid needs something, there is only one box to look in. This would be helpful in keeping storage containers to a minimum and would also help with perspective on how much to keep. If it doesn't all fit then some needs to be gotten rid of, and having one box per child is a good measure of how much is too much. Of course you may want a bigger or smaller box for each child depending on how far apart the child is in age from the next older sibling, as 3 years worth of hand-me-downs are going to take way more space to store than 18 months worth. If you get gifted alot of hand-me-downs from other families then you might want to have all the kids' boxes be the same size for stackability and just have a limit on the number of years worth of clothes you're willing to store. Another reason this idea appeals to me is that I can write each kid's name in permanent marker all over their box. Easy to find and it won't wash off, and when I take their box to do the seasonal switch, I can put anything that's still going to fit them next year right back in the same box. Less boxes all around makes things much easier. If I am feeling picky about sorting by size and season I can always use large plastic bags like trash bags to sort the clothing out by size and season within each kid's box. I have liked my system so far with the newborn through 18 months sizes but after that I have not liked sorting it out so specifically, so I believe I will implement this one box per child method for the girls starting this year.
For shoes... I pretty much keep them with the clothes. Babies and small toddlers won't be wearing the same sized sandals next summer as they did this summer, so when I pack up the too-small summer clothes, I pack the sandals with them. My oldest is only 5 so I have not yet had her wear the same size shoes for longer than a season. I've used grocery bags to wrap the shoes in to keep any shoe dirt from getting on the clothes, but usually I throw them in the washer before putting in storage. Most sneakers actually wash just fine on delicate in the washing machine, if you don't wash them too often. The most important thing I've found about washing shoes is that the leather ones should be firmly stuffed with socks while drying so they don't shrink as they dry, and don't wash on hot as it can dislodge the shoe glue. Light up shoes obviously don't wash well, but if you have to then use the shortest wash cycle and dry them completely before attempting to light them up again. Don't attempt to machine wash girls' dress shoes or any shiny patent leather shoes as the washing machine is likely to scuff and scratch the surfaces. Shoes dry best in a sunny windowsill or outside. Shoes and clothes dryers are not good for each other. Shoes are mega loud going around in a dryer, and the heat from the dryer will melt the glue while the spinning will warp your shoes' toes by curling them upward. If the washer seems to curl your shoe toes too, stuff them with socks to reshape them and dry in a window for a day or two. When the outsides are totally dry, remove the socks so the inside can dry. Always put your fingers deep into the toe of the shoe and feel for any dampness before putting shoes in a closed storage container. You wouldn't want damp shoes to make moldy spots in your box of clothes or shoes.
Swap Day is an all day job so don't plan this on a day when there are other pressing chores or places to go. Try to be as caught up as possible on laundry and keeping the kids' rooms clean in the days leading up to the day of the switch. If you know you'll have more laundry of a certain load on switch day, make sure you leave enough in the hamper to make a full load on switch day morning.
Dress everyone in clothes that are STAYING and not going to be switched. Let them be mismatched or wear holey clothes or even their jammies all day, just so long as what they are wearing is something that will not be switched out. You can change them again later after you finish the switch if necessary.
Get completely caught up on all the laundry. No need to put the items which will be switched away in their drawers/closet - just leave them folded in the laundry basket but IN the appropriate room so they get sorted with the appropriate sizes.
Pick one room to start with. I'd pick the room that has the oldest kids going to the youngest, in case some things that are not seasonal that are too small might be passed directly on down rather than putting them in storage.
Clean the room or have the kids do this the day before so that you have floor and bed space for sorting on.
Go into that room with a notebook and pen to make a list of any missing items, and a bag or box for throw-aways and a bag or box for give-aways. Start in the "too-small" box(es), then move on to the laundry basket, and then the closet, and finally the dresser. Take out everything that's trashed, out of season, or too small. Put give-aways and throw-aways into their respective bags or boxes and make piles by size/gender in the middle of the floor of the out of season clothing you are going to save.
I keep things that are still usable but full of holes or stains out to wear as play clothes indoors, pajamas, underlayers, smocks, etc. If it cannot be used for any alternate purpose and is pretty much trashed it gets thrown away.
Go into the attic or garage or wherever you store the out of season clothes and get the boxes containing the sizes, seasons, and genders you are working with and take them into the room you picked.
Take the clothes you are switching to out of the boxes and put them right into the newly cleaned out closet and drawers. If you seem to have extras of something, either make a small box of "spares" to put on a closet shelf, and put the rest back for a future kid or put in the giveaway box, OR if you use the one box per child method then just store the spares in their box and when they need something you can go shopping in their box before you go shopping at the store in case they have a spare. As you go along, make a list of any items you need to purchase or need more of for the kids in that room.
Take your piles from the bed/floor and put them in the appropriate boxes. Take boxes you're totally done with back to the attic/garage or wherever you store them, and ones that you will use in another child's room into that room.
Repeat from step 3 with the next kid's room. Take your list notebook/pen, and your throw away and give away bags/boxes with you when you change rooms. When you are finished with all rooms, put your list in your purse and your give away bag in the car. Throw away the trash and put away your notebook, pen, and laundry basket(s).