This article addresses motels and small hotels doing their own sheets and towels - I'm assuming larger hotels with in-house laundries have nice gear, expert staff, and proper, albeit small, ironers.
Do it yourself?
If you are going to do your own sheets you will ideally need 4 complete sets. If you use 30 kings to make up all the beds you need 120 kings in total: 1 set on the bed, 1 in wash, 1 on shelf, and 1 for emergencies because you won't be able to ring up for more.
You will not get the same life out your sheets and towels as a professional laundry does - their equipment simply washes and maintains whiteness better, with less damage to the cotton, and a crisper feel and look to the sheets.
To minimise, or do without, ironing or pressing as much as possible you will need a 50/50 Polycotton, preferably around 250 thread count with a finer thread as this has less fabric memory.
We call ours SuperCale. Basically you need good sheets; not budget, not cotton.
The first wash should be at a high temperature (at least 80c) and dried only until no longer wet (leave some dampness).
Immediately press or iron really hot (no more than 180c ever), as this will seal the fabrics memory. If you are careful you may never have to iron or press them again. If they get too crinkled later then repeat this starting process.
On regular washes under-load the washing machine to about 80-85% of full capacity, remove from wash immediately and under-load the dryer so they never get squashed. Remove from dryer and fold immediately.
Each stage in the PolyCotton wash cycle should not change in temperature by more than 20c, e.g. 80-60-40c etc. So don't do a hot wash and cold rinse as this causes 'thermal shock', i.e. shrinking and creasing. Tumble dry no more than 100c.
So that's how to limit ironing or pressing. Next, the hard one.
Keeping sheets white
The most difficult thing for you to do is keep the sheets white. You want Polycotton sheets as pure cotton will need lots and lots of ironing, but polyester is grey and does not absorb whiteners well, so the sheet will slowly start to look a bit grey. Excessive bleaching (including sun drying) of polycotton will result in the fabric turning yellowish - not good.
A laundry uses optical brightening agents finely metered and adjusted - you can but use good quality detergents that will have some in.
Detergents designed for white only are good as they can use more optical brighteners. Ultimately there are so many things (like the waters alkalinity) that you cannot control but can make a huge difference to whiteness and detergents ability to work.
If sheets or slips look yellow after ironing it is usually residue chemicals left on after wash that are then cooked by ironing and turn yellow. You especially need to look at alkaline levels.
Only leave sheets and towels in the sun until not quite dry and then finish with a tumble. Our strong sun can hurt the cotton, especially in the hems, bleach towels white, and cause 'flagging' in sheets (looks like a flag that has been left in the wind too long). Just be careful and don't leave them out there too long.
It's not easy doing your own laundry, many give in and return to the easy care and consistent quality of a good laundry. But if you have good equipment, good quality commercial grade linen, time, patience, and maybe staff to help, it can work if you're careful.