For Runes,I pick amour runes as rammus passive turns part of the amour into damage thus making him a great offensive tank

For masteries.Mostly is defensive types and as rammus get lots of assist,the masteries will help him get gold for each assist or kill

Items are amour based.Thornmail is very important as the starting item as it gives rammus enough atk power for late games and it also allow him to put his taunt into great use.Warmog is for health.Frozen Heart will give rammus lots of amour and slow enemies atk spd,helping allies and rammus.Force of Nature is actually exception ,u can choose it or GA because if u are verusing a team with pure ad,there is no need for force of nature so u will rather choose GA.Randium is to slow enemies down when they are trying to escape.

I max taunt first as i am usually what u call a humji guy.I will hug the tower and play safe until the guy comes close enough for me to taunt him and make the turret wack him,giving him lots of damage and getting the kill.After u taunt,U will on the second skill as it returns damage,Increases ur amour and magic resistance.Only on the power Ball when ur going somewhere in a hurry or when ur taunt is over and the guy is running away

For this,I will pick flash and heal as both are great for tankers.Flash can help rammus to escape and heal can save teamates or himself

From this build,I hope that more people will use good Rammus and Tank better