When I hang sheet rock I always look to reduce seams as much as possible, and to reduce waste as much as possible. This usually means using 12' sheets whenever possible. While finishing my basement the past year I probably threw out 3 trash bags of cut off pieces, none were usable. I also make sure I off-set any butt joints so I don't get an 8' butt joint across the ceiling. If hanging it vertically allows me to go wall to wall without a seam in the middle that's the way I'll hang it. When I was doing my basement I could have hung 2 walls that are 9' high vertically or horizontally. I bought 54" drywall and hung it horizontally. I did wind up with two butt joints on the one wall because there were no obstructions and the wall was 13' wide. Due to supply chain issues, I couldn't buy 10' sheet rock to go vertically, and would have had much more waste going vertically if I bought the available 12's or if I used 8's I would have had more seams. Hanging it horizontally also makes a stronger wall less likely to crack because the drywalls spans more studs, and the vertical seams are offset.
That all said, I've cleaned up too many messes in my volunteer work coming in after people who THINK they know how to hang sheetrock. The one case I mentioned above was the worst, rather than hanging it horizontally they ripped the drywall down to meet the studs creating several floor to ceiling butt joints and a big mess on the ceiling. Our local Habitat for Humanity chapter hires out the sheetrock work because a pro-crew can come in and complete a house in a few days versus a month of weekends for the volunteers. Our chapter hires out roofing, electrical, HVAC, plumbing, and siding if the house if 2 stories. The basic carpentry, trim carpentry, cabinets, decks and the like are done by volunteers.
That all said, I've cleaned up too many messes in my volunteer work coming in after people who THINK they know how to hang sheetrock. The one case I mentioned above was the worst, rather than hanging it horizontally they ripped the drywall down to meet the studs creating several floor to ceiling butt joints and a big mess on the ceiling. Our local Habitat for Humanity chapter hires out the sheetrock work because a pro-crew can come in and complete a house in a few days versus a month of weekends for the volunteers. Our chapter hires out roofing, electrical, HVAC, plumbing, and siding if the house if 2 stories. The basic carpentry, trim carpentry, cabinets, decks and the like are done by volunteers.