Try to not go in combat until lvl 6 when you get your ultimate (R). When you go into combat make sure you have two turrets out, Try to stun the enemy with your E and then use W to make some damage :). Remember that Heimerdinger has very low hp. Heimerdinger is a good pusher so he is very good to go mid with.

Put out 2 of theese very close to each other. Let them push and do nice dmg :)

Use this when a champion is close to you, it blows out three rockets that does nice dmg :)

Ch-1 concussion grenade Use this and try to get the aoe right on the guy u want to stun, the whole aoe blinds the target but if its in the middle of the aoe the target gets stunned.

Use this when a enemy champion attacks you, It does so your evolution turrets slows and instead of three micro rockets it gets 5 micro rockets.