Well it depends on the resources you have. I have been on a factions server that ran this plugin, and I tried a few methods. So for the weapons, I think the mob spawner monsters don't work, so just build a biiigbig natural mob spawner. For acrobatics, the easiest way is to just jump down from really high places. Farming is really easy, just...build a farm and take care of it every now and then. Sugar canes are the best, but melons and wheat also help boosting your xp.