So, I just thought a bit about this. Don't know if this is an original idea or not.

It's always a hassle to enchant items to get the right enchantment. So this idea, which can be done in vanilla, could possibly make enchanting easier for those who have lots of resources.

Essentially, you have an xp grinder of some kind, and assuming it's not a very fast enderman grinder, you get xp and enchant books at lvl 1. Keep doing so until you have plenty of books of varying enchantments. Then apply them to the item of your choice via anvil. You'll have multiple level 1 enchants and then you keep on combining them to make level 2 and so on. I did some tests and the enchantment levels are usually on the low end, so you can crank out these fast as long as you have the materials.

Of course, I thought of this on a multiplayer server with McMMO and just needed to get sharpness on axes. I realized this way was faster than grinding to 30 on my slow zombie xp grinder (no access to the end) in obtaining a sharpness 3 axe and then trying multiple times for a sharpness 3.

The only con about this is that it's very resource-intensive, but if you're on a pvp server, you should usually have scraps of armor laying around! Durability doesn't matter too much, seeing you're making a completely new item anyways.

Anvils are expensive as well, but most servers have anvils lying around spawn. Besides, iron isn't that hard to collect amirite?