Most of its up to you. A common preset alliance game is a WWI one though, Russia-England-France against Austria-Germany-Turkey with Italy being able to choose his alliance. After Italy does choose his alliance he must stick to it though.

Here's one I'm in now:
http://phpdiplomacy.net/board.php?gameID=6872

Are there any more direct questions that you have?

On this website, once one alliance has won, does everyone typically just vote for a draw or do the remaining countries break alliance and fight for the win?

We typically vote for a draw.

i woulds say the a recreated WW1 scenario doesnt work well. it quickly leads to a stalemate line, the east destroys russia and western germany falls to the west. then it grinds to a halt. better mix it up and have a hopscotch alliance board.

Turkey-Germany,Russia-Italy, Austria-France-Eng
Thats one I've played before, which worked well. Another nice one is to talk to the players first and pair up based on real-world locations. Thus you are allied with people who you are going to be able to communicate with easily.

There is also a variant idea called Formal Diplomacy where each country has a declared Alliance/Neutrality/War status with each other country.

If you are allied you can write support orders for your allies and you can move into their territory without it converting to yours. (including supply centers) you can also convoy their units and be convoyed,

If you are neutral you cannot enter their territory or dislodge their units at sea.

If you are war you can attack them but you cannot convoy them or support them.

with each season you declare changes in status:
Allies must be mutually declared and ends wars
War is unilateral
Neutrality breaks alliances but mutual declarations will end wars

We played one a while back where we set players in preset alliances with the seventh man being on his own. We had some chat rules as well but we agreed they sucked. Interestingly the person without an ally (xgongive2ya if I remember correctly) won. Everyone was courting their support.

Thanks so much - this makes it a lot clearer. Has anyone ever tried France-England, Russia-Turkey, and Germany, Austria, Italy?

That alliance structure sounds quite interesting.

I tried FE-RT-GAI on facebook diplomacy.

I was Turkey.

Russia and I swept the board, I think it is unbalanced.

That's what I was worried about - thanks :)

FIA-EG-RT