I use this heimer build, and it works great.. most people underestimate heimer, and this build causes you do be very aggresive and lets you control the map with clairvoyance.

Magic pene. (duh)
mana reg (mostly for early game aggresive play with rockets. you don't need clarity.. with those runes and the ring you have enough mana reg for early game aggresive playstyle)
AP (for that extra bit of damage)

15% magic pen+ 15% faster summoner spells.. standard for pretty much every heimer.

Dorans for the start, you don't need pots because of his passive.. and most heroes you lane against, solo or with a partner will try to stay out of your rockets range if you play smart.. after that get some boots and then a tear for more nukage time.. golem is not needed with this build, but it is still really good on him.. so try to get someone to help you with it early on if possible. after that just max magic damage.. the order of the last 4 is really up to you..you can even get a meja's if yuo are dominating..

First a turret.. at level one to five you can use it for minion kills, but if they have a jungler i usually use it to scout once i have reached lvl 3, because i am good at last hittin and have enough mana reg to use rockets for creep kills... at level 4 you want to get grenade, because.. damn you have no idea how many times i have been ganked, and then as soon as they were within range of my tower i turned it around and got a kill on them, sometimes even 2 because i stunned them with the grenade... upgrade at level 6, after that just max your rockets/turrets and then grenades... 2 turrets placed well at lvl 12-13 can easily change a teamfight to your favour.. the extra cooldown reduction isnt really worth it till later on.. thats why i go with maxing the damaging spells first.

flash, because it's still awesome for escaping and jumping in the score the kill.. and clairvoyance, because it lets you scout easily without having to go into danger.. and we all know heimer isnt the fastest and this build is pretty squishee so you'd wanna not go into bushes to scout..unless you know you can score a kill

Use your rockets only when there are 2 minions or less between you and the enemy hero, that way you can pressure him right of the start.. and don't worry about being to aggresive.. his passive lets you regen health pretty fast at the early game

Hmm, i hope this will help some of you heimer's out there.. if you need anymore tips hit me up @euro Pet3r Pwn
@us Kaiser69andi

i'm by far not the best heimer out there, but i have found this build to be very efficient and yes, it does make people qq about how op heimer apperantly is.

PS:
Don't mid vs mordekaiser.. god i hate morde.. he will just laugh at your rockets all day with his passive shield.. i have yet to beat a good morde @ solo mid with heim.

PPS: yes i did copy this build from myself, because i posted it as a guest.