First wave you'll want to do the secret with the DDR machine to get more mana, then make sure to build all the minions, then either build two temp strength drain auras or (If you have the time) build the buff beams. If you do try to build both, make sure the auras don't touch the buff beams, otherwise they're going out with them and thus have been a waste of mana.
Second wave is where you'll want to build the auras, traps and buffbeams (If you didn't build them on the first wave).

Make sure to have a dps with alright dps stats, or a jester with a decent genie if you want to upgrade everything. A Jester isn't needed, but helps a lot if your dps isn't that great. Make sure to only engage the ogres inside of the auras, as while you're outside of them, you'll take heavy damage and if you get webbed will be killed.

The last three waves, be careful at the end of them as there will be Djinn and Ogre spam, thus putting lots of pressure on your defence. Tend to where the pressure is at most, whether that be the most enemies or the minions with the lowest hp.

If minions are getting snipped too much, add 1DU Reflection beams infront of the minions or if you're having trouble putting all the minions on the 4DU and still have them block the paths, then extend it to a 5DU beam.