Leap frogging is a technique used to clear away creeper and make more ground for building. Two or more blasters are placed next to each other. One of them advance to 3 or 4 blocks away, while the others protect that blaster. Then the others fly up next to where the blaster is while that blaster protects the others. Place some collectors on the space the blasters cleared. Repeat. Wammo!! And you've win.
Leap frogging is very useful. If you are stuck in high ground and have little energy, build some blasters and leap frog some space for collectors. If you are stuck inside a trench, build some blasters and leap frog them out to prevent creeper from drowning you. As blasters can fire 50 shots before it's out of energy, don't be afraid of putting them on creeper.