I typically list a 48 states flat shipping price, and put in a note to contact me before bidding/buying for a shipping quote if they are AK/HI or international. I could care less where the item goes or how fast it gets there...the buyer foots the bill...why would I care?
The only time I had an issue was an order of parts going to HI. The buyer paid for the item and standard shipping(he hadn't contacted me beforehand). I sent him a message explaining that there are additional fees outside the continental 48(which was clearly stated in the listing), and that he owed an additional $12 or something. The guy got all pissy, claiming that he had already paid for shipping and that I wasn't allowed to charge more to ship to HI(did I mention he had zero feedback?), that was discrimination, he was going to report me to ebay, yadda yadda yadda. The next day he paid up and sent a quick "apology" saying that he was new to ebay and didn't "fully understand" how things worked. I sent his parts, and then the bastard left me "neutral" feedback saying the shipping was "awfully slow", when I know it was delivered in 4 days, NY to HI.
Typically with international orders(I sold a few outboard motor mounts to a guy in Germany over the summer), they pay for the item and the "regular" shipping rate, then I send them an invoice with the additional shipping fee. As soon as the additional money is sent, the item is on it's way. Seem to remember it cost like $35 to send a smallish box to Germany. A week later the guy thanked me for prompt service and "very fair shipping fees". I bill shipping at what it costs me. I hate sellers who list items for seemingly bargain prices, and then charge like $20 to send a small envelope via last-class snail mail. In the end it works out to about the same as other sellers, but I will avoid these sellers just because their practice pisses me off.
