I think it depends on who you are playing... If you have an early speacial Unit

really just want that Golden Age

... It just so happens you start a war trying to get it
But that is not necessarily bad. Often I use a strategy to war right away. I consider anyone I meet an agressor trying to take my rightful land ( even if it is clear across the continent

)
So once I find someone (time ofcourse depends on civ total and world size) I head into war. If more than one civ is contacted early on I pick whcih has a superior tactical position upon the other. That way once I hurt the other into submission I am set up for a new target.
It is imporant to not get involved in to many wars at once... So if you see your future enemy building up and preparing make peace with your current enemy. It is often best to immediately engage in war with this war mongering fool on your border
However, since this civ has not likely been involved in war they have more infrastructure than you. Therefore you need to equalize the playing field before you can actually 'gain' from this war. Do this by taking no prisoners (cities). Lay everything to waist.

It may seem waistfull but you won't think so if they come storming in and take them all back.
After you have laid a good amount of your new enemies cities to waist see if they will give you some tech for peace.. Or some cities. Once you acheive peace again stay that way until you get hungry for some new blood
Try to avoid going to war with the same civ over and over again... They will do crazy stuff if they get too
![Pissed [pissed] [pissed]](/images/smilies/pissed.gif)
IMO. Best to in fact make them happy after you pulverize them and become strong allies... And you can always know who is the true master
