Here is a guide that will make you feel much stronger tank than you would usually do with Malphite. It gives incredible teamfight potential in addition to malphite's 1v1 capabilities.

The rune set allows for good early game survivability as well as dmg ratios and harassment.

Masteries are simply proving to be essential for survivability on lane and farming as well.

This item set will give you a lot of health, armor and damage as well as if you are a bit more lucky some critical hits. As well as some supportive auras for the team and mallet proves to be a great hunting tool. The mana regen and health regen as first items are incredible addition to your lifesteal and health/resist from runes and masteries, that will allow you to totally dominate your enemy on the lane with your passive and constant harass with Q spell. Meanwhile you will have no problems farming with your W. Later on your W splash stacks with Tiamat and lets you deal more dmg to other enemies than to the main target. That way you prove to be great dmg dealer in teamfights. The health and health regen items are good for any tank, combined with atma gives even more dmg you can deal...

Your main priority will be to harass and farm. That's why you do not need to waste mana on your E, however you still gotta up it atleast once since it has a good armor dmg ratio, which you might happen to actually need.

The whole point in this build is that you do not get ignored as a tank. When capable of dealing tons of dmg, your oponents won't ignore you even when you are tank and there are more improtant targets like carrys. Play malphite on top and constantly harass with Q while not caring for the enemy harass cuz of your passive and utility runes and masteries. Farm as much as possible.