I've basically created two 5 man teams designed for summoners rift.

The teams are balanced damage output with a 2 tank scheme. The idea is to be tough and annoying with CC while your buddies nuke. MMO dungeon style.

My basic philosophy with masteries is that if you can take a point to support a summoner's spell while getting a max reward out of 1 tree, then you should. To illustrate this point look at the AP tristana on team 2. She has ghost and ignite. Tristana is damage based so the offense tree is an obvious choice. The point in ignite here also lends to her ap while it is on cooldown. 10 points of anything is a lot to get from 1 mastery point. The damage speed and other buffs are like 1 to 1 points spent ratios. That aside I also spent points in utility despite my love of the defense tree. THis I did to bonus ghost because its awesome for chasing, running to another lane or escape. Useful spell. Tristana specifically benefits from this like any character with some AD...she is good at running and shooting. Ghost makes you better at this.

Option 1

Rammus Jungles
Ashe and singed bottom lane
Veigar Solo mid
Morgana Solo top

I love the 2 solo scheme because it increases the average team level and makes them more deadly in early team fights(carry lvl 9 or so). The jungler can also advance quickly if he gets a few ganks in. Essentailly you have 2.5 - 3 carries on your team while standard strategy gives you only 1. You have to carefully choose your top solo(or the one solo that will face 2 enemy champs). Morgana is great for this because of her CC and spell vamp. She is also wonderful when over leveled. The hope is that your enemy will be aggressive and feed. Veigar is best to go 1 on 1. Rammus is an amazing jungle. Power ball makes him very fast too, allowing him to come to the aid of other lanes and gank. Also in this theme of keeping an eye on lanes...he has fortify in case he cannot get to a point fast enough. He can also combo this with his taunt and kill near a turret.

Now Ashe and Singed have a cool synergy. The movement speed of singed's build basically lets him keep pace with any champ and outrun them well enough to poison. His adhesive will help. Further assisting this is Ashe's frozen arrow. The best situation to get is to have Singed fling an enemy between him and Ashe. Ashe will keep them behind Singed. Singed will be able to keep pace and possible Fling again. Vortex of Doom!