I have a deep space above my washer/dryer...

instead of curtains to hide the water heater and softener why not hang shutters that go all the way up and also hide your nifty storage area

You should do a pull down shelf. That way you get full use of the cabinet. It looks expensive though. Maybe a homemade lazy Susan that fits the shelf nicely. IKEA has small ones that are affordable.

i would make a floating shelf that stretched all the way to the front of the machines and maybe hang a curtain above that to hide the storage.

I had this very same problem. The very first thing I would do is start fresh by moving the washer and dryer out and cleaning that area. No doubt you will find treasures you've been looking for. Then, I would move them back and immediately build a shelf that lays on top of the appliances that you can easily slide out when needed! Whether you soften the edges with those rubber edge pieces that can be cut to size or seal the cracks left between the wall and the wood with sealant, you will be so thankful you don't have to worry about losing things anymore. This includes the round area around the heater. If you build a simple wall around the water heater (removable, of course!), you can add shelves to the left of it. You can also hang cute 'laundry' signs in front of it and place hooks or small floating shelves in front of it for simple storage like a lint bucket (you can get cute buckets from the dollar store) or laundry pellets. Whether you keep the shelf above or not, you have so many options for storage. Pretty paint, which of course you can get for cents on the dollar at Lowe's and HD's clearance spot. I don't know how deep that top shelf is, but I would remove it and add a rod high enough to hang laundry, but low enough to reach and out enough to have storage shelves, too. My solution for myself was to redo the floor when I got a great deal on black friday and have my washer and dryer stacked instead. I centered them and it gave me great space I didn't have before! I was able to use the left side for brooms and vaccuums and the right side, I finally found the cutest shelves that fit on the right side and went all the way to the ceiling for laundry storage. I kept my rod in place and still use it to hang wet T-shirts and clothes I don't want to shrink. No more losing things I can't reach and no more filth underneath. It's totally cleanable!

you could organise things into storage boxes, label each one so you know what is in each one. Larger items could be put at the back and a chalkboard attached on the wall where you would keep an itinerary of what is at the back. No more searching but you know where everything is.

Thank you everyone for your ideas.