Offensive strategies are the only way to efficiently gain resources by attacking other players in your neighbourhood. Generally, using a monster whose targets are defensive towers, such as octo-ooze, ichi, crabatron, or project X (depending on your level and needs) then combining an attack, in either the same attack wave or another attack wave, the use of high damage / low health troops such as pokies, finks, fangs, or brains (depending again on your level and needs) to work one of the strategies for example:
My current strategy at level 33, finks plus ichis first examine the base for weak spots and well defended areas. Use your catapult to damage or destroy towers (note: A damaged tower is less effective compared to non-damaged). Once you have spotted the best point of attack (Note: Aim for towers that are in range of the town hall, harvesters, and silos) send your tower-destroying troops in, as close to towers as possible. Mine would be ichis once the attack is under way; you may back your ichis up with finks to quickly destroy a tower or towers close to each other as finks will head towards the nearest building no matter what, so make sure to have them as close to silos and the town hall as possible. Once towers that are in range of silos and the town hall have been destroyed, end the attack if low time and low amounts of buildings have been destroyed (Note: If you ended the attack, check to see if you may attack again, if so regather your army, mainly consisting of finks IF most of the defensive towers have been destroyed--if not use a few extra ichis). Continue the attack once your army has been replenished. Use the rest of your high damage troops to hit the town hall and silos whilst they are unguarded or the towers are distracted. Once your troops have mopped up, or you have leveled your enemy's base, end the attack.
If you damage or destroy too many buildings--usually around 25 percent of base damaged or destroyed--your target will get one 24 hr protection period, meaning you (or anyone else) cannot launch a new attack wave on the target base once your current attack ends, for the next 24 hours (Note: Walls do not count as buildings). Also you only have a maximum of 4 attacks in a short period of time before you trigger the protection mode. So make them count!
Try to use the lowest leveled and most goo-saving troops as you can to maximize profit. Higher-level strategies may include other units such as D.A.V.E (very hard too use effectively), project-x, or wormzers. High-speed units (bolt or pokey)can be dropped in before the more expensive troops to effectively act as 'meat shields', drawing the fire of towers and exploding booby traps, while your army's main body moves in closer.
ATTACKING WALLED BASES
If the target you're attacking has created a wall around their base, a multi-wave approach works best. Send in all your monsters that have defensive towers as their target, but split up when there are splash towers.
Usually use your twig missle on lasers or teslas, and pebble bomb on tightly grouped towers.
If somewhere around 25% of the target's buildings (of all kinds, excluding blocks) are damaged or destroyed, the target will enter the damage protection mode once that attack is over. However, by specifically targetting defensive towers, you can generally avoid tripping the 25% percent cutoff point; usually the total number of defensive towers is much less than 25% of your target's total number of buildings.
You can attack two or even three times until all (or at least most) of the towers are gone. Any surviving tower-targetting monsters will switch to going after whatever is left, and if you have them, fling in anything else you've got. Now is a wonderful time to have a big herd of Finks, as they're cheap and do a good deal of damage even if there are only ten. They will make quick work of all remaining buildings, and will potentially allow you to loot a vast sum of resources.
Keep in mind, however, that once you've taken out all you can in the time you have available and your attack ends, the damage protection mode will activate over the target and you'll have to wait until they come out before you can repeat the process.
LOOTING BASES EFFECTIVELY
Even another strategy, is using Ichi's and brains or any other monster with high health or a bolt. the Ichi's take down the towers and the brains loot the rest. this strategy is good because: the Brains will not be distracted by unlootable buildings and loot better. and the Ichi's will take out the towers.
Another strategy I enjoy using, especially with the Monster Lab out now, is I start catapulting out aerial defense towers, then sending in 10-15 crabatron plus one Zafreeti and 6-7 Teratorn. The crabatron will automatically attack defense towers, and as long as you send the zafreeti in after a couple of the towers have gone down, all the towers will focus on the crabatron and totally ignore the zafreeti totally negating the damage the crabatron take. I then send in 6-8 teratorn to take out bunkers, and loot a bit. Usually this wave will not do enough damage to send the opposing player into protection, but it will take out the majority of there defensive infrastructure, so at this point I quickly whip up a few Brain/Bolt and send them in to loot the base.
DESTROING ALL THE BASE ON 2 TURNS
First Wave-verefication needs 30 bolts,4 eye-ras and the rest of octo-oozes
send 2 octo-oozes to the bunkers to see if there are eyras, d.a.v.e.s, banditos, wall monster(ichi crabatron etc) or project x on the bunkers they can survive enough for it.
send 2 octo-oozes if its eye-ras - just send next to bunker to kill one by one
send 10 octo-oozes and 1 eye-ra if d.a.v.e or the others except the eye-ra first send 3 octo-oozes so he can get out of the bunkers when you see that the last one is dying send the eye-ra so the d.a.v.e.s and others die
when the bunkers are clean just send 15 octo-oozes and 5 bolts on the halls to enter to resources to see if there is booby traps
the base shoud have 2 , 4 or 6 halls
Second wave- full destroy needs 3 zafreeties ,drull(if you don't have drull use teratorns) and the rest of crabatrons
first send the crabatrons in two groups to the closest aerial tower after the towers being destroid send 1 zafreeti ( use other if this die) then crabatons with zafreeti will killall defensive towers but to destroy in time send one drull if this is being it send the 3rd zafreeti(use teratorns if you dont have drull) and the base will be fully destroyed.