Use Troops with high hitpoints as a living shield or meat shield for troops with low hitpoints. Troops like the Heavy or Scorcher can take a lot of hits and can therefore be used as a shield for other more vulnerable troops like the Zooka or Rifleman.
Start your attack by deploying some Heavies. The enemy defense attacks the first target within reach (in this case the Heavies) and the other troops behind the Heavies can target the enemy defense from a safe distance.
Attack with Heavies and Riflemen and use Flares to direct them around the reach of enemy structures towards the Headquarters. This technique is usefull with base layouts with the Headquarters in the far back with little or no defense behind it. Be carefull with defense with a long range like the Boom Cannon, Mortar and Rocket Launcher.
Rush or Rushing
Attack the beach with a large number of Troops, mostly Riflemen. Because of the enormous amount of targets the single-shot defenses like the Cannon, Boom Cannon and Sniper Tower have no chance of terminating all Troops.
This strategy is especially effective with a lot of single-shot defenses. Be careful with defense that does splash damage like the Mortar, Flamethrower or Rocket Launcher. Large numbers of Troops can easily be terminated by these defensive buildings.
Use the impressive firepower of the Zooka! Load all your Landing Craft with Zookas and boost your Gunboat Statues so you have plenty of Gunboat Energy. Then start your attack by deploying all the Zookas at once and flare them towards the Headquarters. Cover there path with Smoke Screens just like the technique below with the Warriors. Once the smoke is gone the Zookas will start firing at the Headquarters and deal serious damage! Be very carefull with splash-damage defenses like the Rocket Launcher, Mortar and Machine Gun. Best is to Shock Bomb them while your Zookas are in range.
Headquarter Rushing can be done with Warriors. They move fast and have the ability to heal themselves. Deploy the Warriors and use Flares to direct them immediately towards the Headquarters. Use Shock Bombs and Smoke Screens to get them there without lots of casualties. Warriors do a lot of damage so this attack is very fast and effective.
Be careful with defenses that do a lot of Damage per Second like the Cannons, Boom Cannons and Sniper Towers. These defenses, especially at higher levels, can easily take out a Warrior. Destroy these structures with Artillery or disable them temporarily with the Shock Bomb.