I'm a gold 4 one trick heimer main whos currently has master lv 6 on him. ive been playing lol scene season 5 but only became a heimer main this season. I have a 80% win rate in the gold division with him

always level you turrets(your Q) first and max them every game because it is the core of his kit. when placing down your turrets put them in a triangle formation with two turrets behind towards the sides you and on in front in the middle. level up your grenade(your E) next to get some easy harass, the way you do so is when the enemy laner walks near or in your turret range you try to stun them and if you even just hit them in the radius of your e they will take a charged up turret shot even if they are just a little out of the normal turret range. In the laning phase you want to just farm up (which is pretty easy with your turrets) and only fight if they engage you with in your turrets. you can try hitting them with your stun and if you hit the entire stun also use your W to get extra damage off. when dealing with ganks and allins on you just try to kite around your turrets so they stay in range of your turrets and also your turrets can block so ability.

when team fighting always try to be in your turrets range, as soon as the team starts place down your ulted turret in the middle of in that use all your other ability (on the enemy teams ADC if possible, also during team fights if not already fighting in your turrets range try to place them down while the team fight is happening.

you can solo baron starting when you are lv16 almost full built, it will take all 3 turrets placed down and also having your ulted turret up.

1-you can place turrets on blast cones and than hit the blast cone and your turrets will be blasted over walls you can use this to steal buffs or during team fights in the jg
2-place all your turrets in a bush and if someone blind checks that bush use you e,w combo on them and there dead