Desk Setup
How does one work without a private workspace?
This is a great question and one I have been heavily considering recently, because I find myself in a similar position.
I work in an environment which is somewhat open but have tons of distractions. I also have a walking path which means anyone walking by (of many) sees my monitors as well as causes distractions since we have barely 1/2 wall cubicles.
This beautiful ASCII illustration shows my desk arrangement:
+----------+
| |
| |
+----+--------------------| |
| | | Additional
| | | Path by |
| | My desk | my desk |
| | | |
| +--------------------| |
| | |
| | |
| Whiteboard sits here| |
| | |
| | |
| +--------------------| |
| | | |
| | Colleagues desk | |
| | | |
| | | |
+----+--------------------+----------+
+------------------------------------------------------------------+
| |
| Main walking path with TONS of people walking daily |
| |
| |
+------------------------------------------------------------------+
Now, I also really like having a whiteboard at my desk. I use this all the time and had an extra at home which I wasn't using so I brought it in and mounted it like so:
The net effect this has is twofold. First, I have a whiteboard at my desk which is great. But second, I actually block anyone walking behind me on the main walking path from seeing my monitors unless they are quite tall.
I'm not sure how the private cube mentality is "perceived" by others. Unfortunately perception is usually a determining factor for judgement.
All my coworkers love my setup, because a whiteboard is so helpful. The facilities guy hates it because it looks... hokey, but, everyone else likes it and I've gotten compliments from others about it. Plus the facilities guy actually is trying to find a cost effective but more aesthetically pleasing version anyways.
Perception
To help with the perception element, I've spent time talking with nearly everyone around me about the "needing to focus to be able to get work done as I'm an introvert" discussion. This is the important thing to focus on - the things other people will relate to. Odds are most of your future cube-mates are going to go "man I wish I was smart enough to think of that!" or something like that. But only if you explain the why. My current boss knows this too.
Most people generally can relate to the, "distractions cause me problems working effectively" question. Simply mentioning this, or asking coworkers, "how do you deal with distractions?" can make this a completely not awkward and easy conversation.
How to focus
Get yourself:
- Earplugs (soft foam ones are most comfortable for long term use, learn how to put them in right - I'm not joking, putting them in this way is 10x as effective as what most people do)
- Over ear headphones, I wear these, if you don't like music get yourself more "noise muffling" types
- Baseball cap (like below works)

You can adjust the hat down in such a way that you do not see much in your peripheral vision but still see your monitors fine. If you have a natural "wall" on your desk tilt the cap sideways slightly to block the aisle next to you. Combined with a good set of headphones and earplugs, you can block a very large percentage of distractions this way.
Combined, these three items lets me block all noise distractions and after a while you learn how to position your hat in such a way to block a considerable number of visual ones.
Last, this might be obvious, but close out of email/IM/SE completely and you will nearly completely remove distractions.
When I'm working like this I am completely in my own world and actually feel bad when people need me because I'm completely and utterly oblivious.