1) roll on a pve server
2) join a guild that will step in and protect you
3) deal with it
4) log into a 90 and go get revenge (not always possible)
5) get better
As an Elitist, this is the most common response. I too had this response for the longest time. But then realized that quite a few people become victim to this, even those of us who pvp quite actively. And noone enjoys wasted time.
Roll on a PvE server. A lot of people won't because they have too much time invested into the characters on the pvp server and don't have the means to transfer them.
Join a guild that will step in and protect you. This may not be viable as the conditions are based upon guilds recruiting and the player looking to join a guild.
Deal with it. The easiest of the list to accept.
Log into a 90. As you said, not always possible.
Get Better - No matter how good you are, if there are 5 Blood DK's camping you and you're a priest, doesn't matter if you're the best pvp priest in wow, you're not going to survive that.
Again, this idea is to assist those who are constantly getting killed and have lost all progression due to the pvp activity in that location.