Help me design a diaper bag

[sillygoosegirl]

I want to make my sister a diaper bag for her new baby (due late this October), but I'm not really sure what features it should have as I am not yet a mother myself. I do a reasonable amount of luggage sewing and I am comfortable and even prefer designing it myself without a pattern, but I need to know what kinds/sizes of pouches and compartments to put in it. If it changes anything, my brother-in-law actually does the majority of the "mothering" as my sister works full time and he is a stay at home with the two children they already have (boys aged 7 and 9).

1. I'd love it if I could get a rundown of everything you mothers keep/kept in your diaper bag.

2. How many large compartments should it have? How many small ones? What approximate sizes are good?

3. Are the zip-down baby changing pads useful? How big should such a thing be?

4. Though I intend to design this diaper bag myself, I'd appreciate links to any patterns or comercial diaper bags that you think are particularly good and/or well-featured.

5. How big should the whole bag be, anyway? How big is too big?

6. Features I'm thinking about (your comments invited):
- Two large compartments for clean/dirty stuff (with a soft divider between)
- Easily accessable small pouches for: bottles, toys, books, papers, cell phone
- Zip-down (possibly detachable?) baby changing station with buckle strap so the baby doesn't wiggle off
- Hide-away backpack straps and shoulder strap

[kerc]

My husband prefers a backpack style bag all the time. I have sewn two diaper bags and both are too girly for his manly self to carry :LOL . Actually he'll carry them, but he won't sling the kids so he prefers the backpack for ease of carrying both child and bag.

We use my old school backpack from LLBean -- the basic features of which are the same as this one, only it has only 2 outside pockets.
http://cdn.llbean.com/products/trave...racks_Camo.jpg

We have a fold-out changing pad that's about the same size as the changing tables in bathrooms. It folds in three and we keep it tucked in the back near the straps. There's acutally a little pocket designed for ? in my backpack and we tuck it back there. I don't like the idea of the zip out changing pad because it is just one more hassle. If you have a squirming baby the last thing you need is to have to zip the thing back together.

I like a key clip in the front pocket, and personally I keep my wallet/checkbook in my diaper bag (dh does not).

I prefer tote style bags with 2-3 pockets sewn into the side to keep sippys and water bottles upright.

My diaper bag for newborns contains:
cloth diapers + extra flat diapers for spit up
cloth wipes
a small bottle of water for wetting down wipes (I use a shampoo travel bottle from target)
water for me
small toys
change of clothes, sometimes a new shirt for me
dirty bag (basically I use a drawstring style bag that's waterproof)
+/- sling

If my dh were in charge on most out and about trips he would also need to be able to handle a bottle of breastmilk somehow.

I tend to keep my diaper bag in the trunk of my car when I run in to the grocery store or the like and carry it when I either need to change baby or need to be away from car for long periods of time.

This one is nice.http://www.ebags.com/kelty_k_i_d_s/d...?modelid=49677
Kelty makes another one that has 2 tote handles at the top -- so it is backpack but you can tuck away the straps.

Oh and black inside makes it tough to see what's at the bottom of the bag.