Use the following trick to get easy SP, Materia leveling, and experience. Once you have got your vacation time at Junon Beach, you will have a new mission under the "Mysteries Of The World" category called "Fun In The Sun!". Successfully complete this mission set to unlock "More Fun In The Sun!" The second mission in this sub-category is called "We Hope It's A Vacation". In this mission, Sea Worms fall out of the sky about a half dozen at a time. This conitinues until about fifty have been destroyed. They are easy to kill, but they can hit you with Stop. You may want to equip Sprint Shoes. Once you have obtained Quake Materia from Wutai's secret shop, you can kill up to six enemies at a time in this mission. Doing so greatly increases your SP multiplier. They also drop a lot of MAG Mako Stones for Materia fusion. The DMW seems to react quite a bit to this mission; expect lots of Modulated Phases. This mission never expires. Kill the worms as much as desired.