Need ideas for completeing a greenhouse/shed

Built a new garden shed/sort of greenhouse. Completed last fall. Need some ideas.
What do you wish you would of done in your garden shed/greenhouse?
What did you do that has worked and/or didn't work?
Have you seen ideas you think would be nice additions? ex: I saw where someone took metal trash cans, built a frame so the trash can was titled out and filled with potting soil under the potting table.

This building has a concrete floor, window on se corner, south corner, glass french doors, other south corner, sw corner, floor drain.
Concrete porch with a concrete ramp leading up so it is easy to roll plants in and out.
Small furnace on the north wall. I have lots of cabinets I could install.
Large old cast iron sink.
3 large stainless steel baker racks from costco.

Will use this building for storage, potting, seed starting, overwintering plants in pots(large ee's & tropicals), hanging baskets.

Thanks for your help.
Joyce

Joyce, I like your questions but sure can't answer any. I'm just in the dreaming stages of building a greenhouse/sunroom and would find answers useful. Guess that those who've built their greenhouses are busy working in them now.!
Toni

Broad questions. Pics might give us some ideas.