Start on lower waves around 15 or below. If you can start higher, you probably have the stats to do faster builds than this. Make sure to 3 star EVERYTHING! The Spider Minion above the southwest Gas Trap and the one to the left of it are inside the building's windows. Scroll to zoom out if you cant reach those. 

The proximty mine clears trash mobs on the west, with the other two traps weakening and stunning djinns. Enrage auras play a big role - if your auras edges can reach Hint 4, you can cram up a bunch of mobs, forcing ogres to reroute to the long northern path all the way to the west. Ogres cram up hard and sometimes squeeze through, which is why i put 2 archers behind the main west wall. None of the minions are stacking in Hint 3. Try to have them all on the buff beam while spread out as far as you can. Use monk guardian to connect the west aura stack to the buff beams at Hint 1.Stay away from harbingers. They'll be right out your door and if you aggro them everyone whos buffing will take serious damage. Healing Auras helps mitigate this, but not completely. 

Note** The DU for proton beams on this planner is off by +1, the proton beam at Hint 3 is supposed to be 2 DU

Hint 1 is the juice of the build. The Ethereal Spike Trap instakills any spiders that spawn. The auras are - Healing+Enrage+Strength Drain. Everything should fit inside the light grey circle, with reflection beams fully surrounding without any cracks. Make a cross with 4 DU buff beams and on each beam node plant a Fireball Tower. The middle of the cross should have 5 STACKED LTs. Standing on top of the Lightning Tower, you can heal all auras at once. You want at least 3 Summoners. One with Huntress and Monk guardians on top of the LT stack, and Apprentice+Huntress Guardians for the other ones on top each fireball. More summoners=better. I recommend getting at least 70% resistance on all your boosters. 

Adjust the strategy to your needs. Please comment if you are stuck or have any questions!

Which heroes to prioritize stats?
1. Apprentice - try to get as much stats into Tower Damage as you can.
2. Summoner - the highest you can get on Minion Health, then Damage
3. Monk - In order for the auras to connect, you need high enough Aura Radius
4. Huntress - Trap Radius is important, but the Proximity Mine's charges go off extremeley quickly, so you want as much Trap Health as possible for less frequent repairs