Ugh. Where to start? Don't make it PT staff only. Look at actual desk usage - the areas in my organisation who run it best tend to make senior staff hotdesk more often as they spend so much time in meetings, while junior staff are more deskbound. But don't do that at the cost of managers who end up never sitting with their teams.
Think about patterns of attendance over the week - we have peak usage on a Wednesday and it can get really tight. And over the year - January is dire, everyone's in.
If you don't go for full clear desk, you can go for respectful personalisation of a desk - if it's yours 90% of the time! have a few things! but keep it clean and ensure someone else can use it. We have drawers on wheels which are useful if you're not going far, but not if you're on the other side of the building.
Think about special fit when setting up the IT - specialist keyboards and mice are easy to deal with as long as you don't have to firtle about round the back of a PC to plug them in (been there, done that, lots of stress and dusty knees, and one broken PC).
Have desks bookable, not first come first served (we do), enable mobile working (we do this a bit), and working from home (we barely do this).
All that said, I'm currently at a desk of my own, in an actual office, and I love it. Not looking forward to going back to hotdesking (technically it's desksharing, iirc) in future.