Welcome to my Heimerdinger guide! This is built specifically for the recent rework. I will take all criticism into consideration.

Heimerdinger is quite unlike other champs in the use of his abilities. He revolves around the use of his turrets. The number one dinger strategy is to place 3 turrets in range of each other, when the enemy attacks you evade them while the turrets wear them down. Stun them with your CH-1 Electron Storm Grenade when you can, and spam your rockets. When you have your UPGRADE!!! choose wisely. If its a 1vX (x is your team) I suggest using Hextech Micro-Rockets, if it's a 2 or 3 v X try your CH-1 Electron Storm Grenade. In team fights use your H-28G Evolution Turret to slow down enemies hoping to get to your backlines, and to apply consistent damage over the duration.

Heimer is pretty good at deciding where to hold a lane. If he wants the lane consistently pushed he can put his turrets on the enemies side of the lane (side of the lane is determined by the point where opposing minions meet on the first spawn, without champion interference.) If he is playing a more conservative lane he can keep his turrets back by his caster minions for protecting his lane from getting pushed without pushing too hard. If heimer is working in a pushed lane with teammates around, he can place his turrets near the river to help prevent ganking, and to zone out the enemies.