As a trial run to finishing my basement floor, i tried doing the garage floor. It cost me about $1.25 per foot, rental and supplies.
The pictures don't capture exactly how it looks in real life, but close enough.
I rented a concrete prep floor sander from HD, and used a concrete prep head on it. I followed that up with two grades of sandpaper, so my work stopped at like 30 or 60 grit.
Once i got used to operating it and keeping it under control it went pretty well. I was shocked at the amount of dust i created, over 100 lbs. It took up the cream (top level of concrete, very fine, and exposed the aggregate). The sanding discs sanded down the gravel to some extent, but they did remove more concrete in the process, so the aggregate is every so slightly exposed. Walking barefeet the floor feels smooth. But close inspection on hand and knees reveals the result.
I then stained it with H&C stain from Sherwin Williams, and followed that up with their Oil based Glossy Concrete sealer, bout 5 thin coats.
The staining process revealed the areas that would accept stain, the white shapes. The sealer revealed the areas of differing fineness of sanded finish. I was not able to get the entire floor to the same level of luster.
I'm going to do my basement in this manner, but i'm going to rent a better (i think) machine from Sunbelt rentals. If i have a bunch of random shapes show up in the basement, i may try cleaning those areas, but i may leave them, Up for suggestions on that issue.
I'll also use a different sealing product, the oil based one for the garage stunk to high heaven, no way i can use that for days on end in my house.
Here are a few pics, more to come.