These are some things I do when I am going for a perfect game.
(This guide does NOT cover strategies for specific towers as a main)
Towers
1) Start out with either a Scientist (XP per attack lower DPS), Dandelion (Fair against any creeps including single targets + AOE damage) and Rabbit (can take out air better then most since it hits mutiple targets without the need for them to be near eachother).
2) Place the main tower somewhere either in the middle 2x4 second or the lower 1x3 (depending on who your primary tower end game will be). Placing your main tower on the ^ or the \ on the upper part can make for end game ease if you are going to use Gib.
3) DO NOT fill every space possible untill you have passed several waves (~20+) this allows your main tower to gain as much XP as possible allowing him to get most of the kills. This lets you make sure you will always do as much damage as possible
4) A. During Challange and Horsemen waves replace your primary tower with a Scarecrow as soon as you kill the final creep of the wave before (make sure he only has damage items on NOT attack speed) and DO NOT skip the wait in order to make sure your Scarecrow has max crows. After your Scarecrow gets off a single attack (should be with the mutiple crows) Change him into an Hitman or Poisones frog (adding an attack speed item is fine for them)
4) B. If you do not have a Scarecrow you can use a Poisonous Frog as they are also very good for single target (using 1-2 Magical Mushroom and/or Seven-leagues boots is also very good here). After the Challange or Horseman has reached the edge of your Poisonous Frog's range turn him to an Hitman
4) C. You can also use a Hitman from the start
5) Fill all blocks within 2 squares around you with Herb Witches. After getting your main tower loaded with some attack speed (from pots or items) you can replace the Herb Witches with Beavers and Hulis (they stun/see tip 12)
6) (OPTIONAL) Use Elvis on locations that Herb Witches will not gives you there buff. Careful placement is recommended as they can hurt more then help
7) Horadric Cube should be placed on the very last square most of the time
8) Manitou should be at the very limit of where his buff will reach your primary tower
9 A) Ganesha should be place in a location that will allow it to buff as many towers as possible wile still buffing your primary tower (see tip 9/10)
10 A) Dark Forge placement should be within range of Ganesha's buff and keep him till he gives a "Dark forged blade". See this post for a more details (see tip 9/10 part 2)
9/10 B) Depending on if you wish to keep Dark iron forge and Ganesha as themself when they hit level 99 you should place them next to eachother somewhere before your primary tower. After they hit 99 you should change them to a Gib and Black Widow
11) If you so choose place Black Widow & knusperhexe (give knusperhexe any extra attack speed items, Helm of Hades is also good for her) near the front where your primary tower willstart attacking first. After Knusperhexe has 120 stacks of "Eaten" equip her with enough pumpkins to give her 60s cool down
12) Beaver & Huli The Monkey can be used to fill extra places for there stuns
Items
1) Your primary tower in the beginning should use what ever you can. Best to worst(DMG->XP->SPD->CRT->OTHER)
2) Always keep atleast 1 Longbow in the beginning for air waves
3) Use Pumpkins on extra towers to lower there attacks so your main tower can get as many kills as possible (unless you think you will need them attacking)
4) Handbag, Gold coins & Ring of greed are generally trash and should be transmuted with your Horadric Cube (Use Gold coins if you plan a Sat build)
5) If your primary tower does not have 100% crit chance Fistful of Steal should be given to all towers directly next to your primary tower (if you already have 100% crit chance then they should be transmuted)
6) Use every Key of Wisdom you can get your hands on!!!!!!
7) A. Only equip Messerscmidt's Reaver (when absolutely needed) forgetting you have it on can hurt you a lot)
7) B. Equipping Gib with Messerscmidt's Reaver will allow his slow to effect all creeps in the splash range (VERY GOOD)
8) Equipping Gib with the full Withered set will be a HUGE help on challange and horsemen
9) A. Equip all Beavers & Huli with Seven-leagues boots (4 of them if possible)
9) B. At about tower level 45-50 Magic Mushroom will be more beneficial then Seven-leagues boots
9) C. When ever you get an extra Rotten Toadstool and Dried Cactus (Withered set) equip one of each on a Beaver/Huli if you have an extra Gib it will do well on them to (Fastest attackers first tho)
10) Use potions on your main tower the moment you get them. The level bonus of potions wll take effect for future levels even after the use.
11) After your primary tower has enough attack speed potions to let him have 0.1 ASPD with only one item or less give the remaining attack speed items to Gib till he has 0.2-0.1 ASPD with only 1 ASPD item.
Using these as a guide you can get a 100% kill game with some luck (dang RNG!!)
12) When trying for pure damage equip Excalibur, Dark forged blade, Frozen heart and another Frozen heart OR Dried Cactus
13) Essence of Wisdom will give the most benefit if used as discribed in the Dark Forge guide.
14) Painkiller should be saved to be used on a tower at the end of the path to save yourself or takeout a challange wave that is about to escape (3 second countdown till BOOM)
15) Soul flask to be used on a trash tower for a little extra life
