As yellow on Craters, you’ll often be allied to blue. You should get the firestorm stonehead (blue rarely gets it), and will have to keep in mind that your enemy red is likely the one with the firestorms, and he’s likely to use them on blue rather than you. You’ll want to focus on doubling red. You can back door green.
As quickly as the game starts, charge only convert and keep converting until you have about 25 people. Then start charging landbridge immediately, and use it as shown above. You can get the hill in 3 LBs, but red can get it in 2 LBs. Take the hill, pray for volcano (which you can use on either of your enemies), and build towers there. You can build a tower on the hill and landbridge to red’s base with 1 LB; this is a good way to attack. You should try to take red’s firewarrior hut out and double him. Blast the braves praying on the enemy team’s firestorm stonehead as well, and the trees nearby. You can camp on the hill while charging earthquakes, and getting volcano and firestorm from the stoneheads.
When on the hill, you can wait for green not to be in his base, then use 4 LBs from the hill to landbridge to his base, and drop a bunch of spells from him. You may as well side green from your base, or backdoor green.
Green’s hills can easily be land bridged, and, even more destructively, you can get on one of his hills and then landbridge another hill.
Mid-game, consider filling in your crater with landbridges in order to build more.
1v1 between Electric (yellow) and aravinth (green) (blue is playing on yellow’s land, red is playing on green’s land)
1v1 between Electric (yellow) and TheDarkAngle (green) (red is playing on yellow’s land, blue is playing on green’s land)