A lot. But generally speaking, I won't order anything online that a. i have to pay shipping for, b. can't return to a store or doesn't have free return shipping. The only exceptions being some stores that pretty much never offer free shipping, unless you spend x dollars. Or if its for a gift or something you simply can't get anywhere else.
IN those cases, I generally wont' buy anything unless there are several items I want, because in my mind, its not worth paying $8 to ship for one item, but for four it is, since then its just $2 per item. I know that's weird, but that's how my mind works.
I will ALWAYS look for a free or reduced shipping code and usually can find something. Even if its a 20% off code, then paying for shipping isn't so bad.
I order from all over, Makeup, beauty products, clothes, and I’ve recently started order a lot more from Amazon since I now have Prime (for a set annual fee you get free 2 day shipping). I signed up for that when I got my Kindle Fire so I could stream videos, and between that, and the shipping, well worth it to me.
The one thing I will not do, howver, is use my debit card online. I just don’t trust anything happening since its tied to my bank account. Credit cards I’m fine with, since if there’s an issue, you just dispute the charge, and you aren’t out any money. But with my debit, if someone gets my info, they can clean out my account, and while I will most likely get it back, I’m still out the funds until its resolved.