No ideas?

Well, other than the obvious ones -- food in the pantry and the fridge... You've shown us the cabinets, but not said anything about the stuff you are trying to fit in them.

Step 1: Get rid of stuff you don't use
Step 2: Put the rest of it in the cabinets
Step 3: If there is leftover stuff, go back to step 1

As a last resort, add some storage to the garage for stuff like the turkey roasting pan that only comes out once a year or so.

Also, the guts of a cabinet can be replaced/reconfigured. If the 4 tier lazy susan isn't working, could you take out a shelf or two to make taller storage? Tray dividers are easy to add after market as well.

As Janet suggests, it would be helpful if you could give us an idea of what sort of stuff needs to be stored. Lots of china? Pots and pans? Small appliances...toaster, blender, coffee maker, etc...or will they be kept on the countertops?

Also, you say there is "empty space" under the cooktop...not sure what that means. A cupboard with nothing in it, like a sink base? If so, I'd have ROTS made to store pots and pans there. Alternatively, they could be stored in the drawers under the microwave and to the left of the cooktop. Then you might consider tray dividers for under the cooktop.

On the other side of the kitchen, you might consider concentrating baking stuff...near to the mixer. Some folks have found base lazy susans to be good for bins of flour, sugar, etc. Perhaps a pull-out base could work as well. In the top lazy susan...baking soda and powder, large containers of spices that don't fit in the dedicated rack, chocolate chips, etc.

As I said, it would help if we need what kind of stuff your in-laws store and need close by.

Um, thanks?

Step 1 is a given (to us, I know I didn't specify in my OP))as they are downsizing from a very large house/kitchen to very small house/kitchen, so a lot of things are going into extra upstairs storage (she has several full sets of dishes that used to be stored in her old kitchen).

Things to put in cabinets. Hmmm, the usual:

Pots, pans, baking sheets and pan, serving trays, cups, glasses, wine glasses, mugs, plates of various sizes, bowls, mixing bowls, baking supplies, roasting supplies, eating utensils, cooking utensils, dinner napkins, cocktail napkins, corkscrews.

I am specifically asking how we can utilize the craptastic cabinet innerds to make the kitchen easier to work in (ie: What in tarnation do you put in a Lazy Susan cabinet that goes up to the ceiling? What on Earth would YOU put in pull-out shelves that reach the ceiling? Do coffee cups and bowls go over the appliance garage? Wine glasses over the appliance garage since the beverage cooler is just across the aisle? What should go over the sink? Plates?).

My mother-in-law cooks 7 days a week and entertains at least 3-4 times a week for clubs/friends/special occasions/etc.). They only thing that I can think of that she doesn't use more than once a week is a slow cooker.

Thank melissastar, I guess I should have clarified some points so that y'all know what we're dealing with other than the physical stuff.

The empty space under the stove is, literally, a big black hole (well, the downdraft innerds are under there, but don't take up much space). I thought of having her store a couple of large stockpots there and perhaps her slow cooker. The drawers to the left of the cooktop would be used for other pots and pans. The drawer under the MW will store microwavable bowl/containers. The drawer under the double ovens will have some baking pans in it. So, after storing cooking oils and whatnot in the cabs near the stove what else could go there? They just seem awkward to me. Same goes for the storage over the sink after plates and such are up there.

The appliance garage will house a toaster oven and coffee maker.

I like your idea of the baking ingredients and such being put over in the blind pull-out. That could work very well. Pie and cake pans and muffin pans would fit in there, too. Thank you!

OK, I don't know where she plans to prep, but there is no prep storage place in the island anyway. So I'd start thinking this way:

Prep storage/the wall to the front hall. Kitchen gadgets, colanders, rolling pins, measuring cups and spoons. In that corner lazy susan, you have two choices. LS's are good for bowls, so you could put in prep and mixing bowls, as well as serving bowls such as soup and cereal and salad bowls, etc. Or you could use it as an adjunct pantry for things that involve prepping rather than just eating, such as baking soda, powder, spices, flavorings, etc. Coffee and cups should go above wherever the coffee pot is, either on this wall or the sink wall.

Cooktop wall. You definitely need pullouts below the cooktop. Use those for frypans, sauce pans, stockpots, etc. With no pullouts that cab is unusable. Use the drawers for utensils and gadgets used only for cooking--ladles, wooden spoons, tongs, thermometers, turkey basters, potholders, etc. That silly over-oven pullout is tough. Try putting a few light baking sheets or whatever on the bottom, and maybe the tippy top could be something light like tupperware or paper toweling. No, it won't melt. Use the cabs above the stove for oils, Pam, possibly lids with an aftermarket rack, etc.

Sink wall is where the dishes go. Again, the tippy top of the pullout could be used for paper or plastic products.

space under the cooktop is prime, I wouldn't store things not used on a regular basis there. can stockpots be stored upstairs? in a closet? over the ovens?

have ROTS built for under the cooktops (or drawers put in) for pots/pans. if they don't fill it up, use also for maybe large plastic storage containers, larger mixing bowls, or bottom ROT for small appliances - like crock pot. or put a vertical divider there for cookie sheets, cutting boards.

higher up ROTs can be removed. maybe keep the bottom most ROT. store things not used on regular basis up there?

start with basics / most necessary items. after filled up someone will have to determine what of the leftovers is to be kept - and where.

Thank you, thank you, thank you! I just stood there staring at these plans and looking at the actual cabs this weekend and got overwhelmingly baffled.

I really appreciate this!