I can shop OK, as long as I know what I'm getting beforehand, the store's not crowded, and I prefer to do it alone so I can move at my own pace. Crowded stores raise my anxiety, and people hovering around me has me teetering on meltdown, and as soon as I notice it, my first and only reaction is to flee. Every now and then when I exercise my urge to flee, someone will say to me "you didn't have to move," or something like that. No, I did, actually.
As far as Christmas shopping goes, I either go to the ghetto mall on off-peak hours, K-Mart, or I shop online for all the gifts I need. I like giving gift cards when I can because they're quick and easy to pickup, and despite the conventional wisdon that they're impersonal, they can be well personalized based on the store or restaurant the person likes.
Also, I find myself favoring big box stores over mom-and-pops, which bugs me to death, but the mom-and-pops go out of their way to be friendly. Their intentions are good, but I need to look for things on my own terms and don't want to feel pressured into a sale, and like I said before, I don't like people hovering around me. I want to select the product, pay, and get out as quickly as I can. Again, nothing personal, but I just feel suffocated and anxious with all the long conversation