1. Hold level.
The higher the level, the more uncomfortable it will be. Lots of enemies and powerful enemies. Low lvl are usually 'safe'. Moreover, high lvl do not provide additional defense bonus, items, etc.. The trick to hold level? Do not upgrade defense building too quickly.
2. Focus on upgrading attacking power than defensive.
Why? simple, no matter how good the defense can certainly be destroyed by tank spammers. Especially with the recent update, can not queued fixes (hopefully quickly fixed).
3. Do not be have a BEFORE aggressive challenger / mega tank maximum level (or at least lvl 6).
Many alliance are also a bully. The more rarely do we teased them (attack base / depot others) the more rarely do we got attack. Indeed there are a lot of thieves, but be careful when going to retaliate. Preview, whether they are part of the alliance or not. If so, better invited to talk (why steal?). If they do not want, so be it. Write down the coordinates. After being strong, attacked back. Do not be impetuous, it'll actually be a 'farm' and lasting DP
4. Resources (resources).
Easy. Attack just rogue Faction (RF). There is always a level equal to the level of your base near you. The result is faster and safer
Lvl 3 RF: 9.900 lk oil / metal.
Lvl 5: 14 + K lk oil / metal.
Lvl 10 +: hundreds of thousands.
Lvl 20 +: millions.
5. Learning to lure mortar (mortar baiting).
Use dog, Rifleman, buggy, or Humvee. Prepare also tanks (my favorite: razor or challenger) Then send them into the mortar firing range. Furthermore run to another point after mortar fire. Back and forth from A to B. Meanwhile, ordered tanks attack turret (machine gun).
6. Distance is everything.
Note the matter of shooting range. If you've pay attention to this, less likely to fall victim to big on your side. The average tank lvl 6 + is always beyond the reach of turret. Razor had the most long range, even lvl 3 razor was able to out range turret.
7. Use the right unit.
Tanks For destroying the turret. Aircraft (cobra / Warhawk / copter) to destroying mortar. Rifleman For clearing mines and lure mortar.
8. Focus upgrade.
I think, always prioritize the tech center. Upgrade to the maximum level as quickly as possible. Tech center first, then the command center, followed academy. Army adjust to storage tank capacity (the stronger the tanks, army storage upgrade). Oil / metal storage adjust to the needs. This means that if it took 1m oil, make new / upgraded oil storage until it can reach a million. Why? so that do not hurt when stolen by others. Moreover, upgrading storage is very fast. Upgrade tech, command, and academy is really long, so is a priority.
9. Defense.
Well, if you've got strong weapons (tanks, air force , then reinforced mortar, turrets and bunkers plus mine factory. Indeed, the level will rise quickly, but you're ready to face powerful enemies. But if you are to be disturbed a lot from the beginning, no harm strengthening little defenses aka upgrade.
10. Almost forgot, stand ground defense.
Put gatling / hercules right in mortar the position of. Put the mega tanks / challengers right in turret the position of. Then, the command "stand ground" (after the command center lvl 3). If not, the unit will be lured out and massacred by the air force or mobbed. The sign 'stand ground' there is white prisms above.