Falmouth University uses a ballot system where all students are randomly assigned a number and then assigned accommodation in order; as 1/3 of Falmouth rooms are shared bedrooms, you may be assigned one even if it was your last choice, depending on your luck in the ballot.
Students with medical needs are assigned accommodation first based on the room type they require; this can range from allergies to physical disabilities or mental health conditions. If you fall under this category, you need to apply for an individual learning plan (ILP) at Falmouth so you can receive the right room. This is simple to do, and the accessibility team can help you with it.
Obviously, despite Falmouth operating on a ballot system, it is important to put the accommodation you want most at the top of your ballot as you may be picked early enough in the ballot to receive it.

If you're studying in Penryn, I would work out whether you would rather be closer to the University and not have to travel in or closer to town and travel to the University.
As a Penryn student living in Maritime Studios for my first year, I get the train to Penryn station and walk to campus each time I have a lecture. This can sometimes be annoying as I often have to leave 50 minutes before my lectures to get to the University on time. I am also often early for my lectures due to the train timings, but I use this time to study and catch up on work.
The thing I like about living in town is that I do not have to worry about how I am getting home after a night out, I don't have to worry about making the last bus or train home to Penryn, and I don't have to pay for a taxi if I do miss it, as my home is within walkable distance.
Living in Falmouth has also meant that I get to go to the beach a lot more often, as it is a short distance away, and I can go into town whenever I feel like it.
Living in Penryn for the first year can be desirable when there are significant gaps between lectures. If you live in Falmouth, you often don't have time to go home during those gaps.
I also think it is important to look past the location aspects, too. You are going to be spending the majority of your time at University in your room, and it is important for this to be a space you like and enjoy, not just a good location.
Packsaddle is really lovely as it is newer than other accommodations; you have dishwashers and are close to a bus stop and the Penryn campus.
Glasney is Falmouth's biggest accommodation. As another commenter says, the kitchens vary in style and age, with some being much more modern than others. Glasney single rooms are a really good size for student accommodations, and the desks are huge.
Glasney shared rooms are much nicer than people first think; you both get a desk and a wardrobe and most people I know get along with their roommates. It is also important not to worry if you get given a shared room, as many students drop out and free up rooms in other accommodations. My friend was moved out of his shared room a few weeks into University, and by Christmas, you are likely to only be in a shared room if you choose to stay in one.
Maritime Studios is being refurbished, with new blinds, beds, and lights being installed before September. The staff is friendly, and it is really sociable despite every student being in a studio.
The Sidings is a good location. You are right next to the train station but within walking distance of campus. One downside is that the trains can be noisy, and if your room faces the station and is on a lower floor, people can see into your bedroom while they are at the station.
I don't know too much about Tuke, but I know people living there who like it.