Here's a TL;DR about Hextech Crafting i made

• You buy or get chests & keys ingame, then you open them :

http://puu.sh/muHYM/0c22a9ccd0.jpg

• You get either a skin shard or a champion shard, those are not playable, just materials for crafting :

http://puu.sh/muI1v/a9d6024caa.jpg

• You can use them in multiple ways as seen here :

http://puu.sh/muI6F/fcd5b8b3fa.jpg

• In this one, i used 3 of the champions shards i got, you can combine 3 shards to get a permanent content (it's one of the 3 you used) :

http://puu.sh/muIiG/23e45d3f9b.jpg

• Since there was a Draven shard in the process, i got Draven playable and permanent :

http://puu.sh/muIkf/42013afc83.jpg

• If you want one particular item forever, you need to disenchant your other shards to get essences (like Hearthstone dust) and craft it :

http://puu.sh/muIXB/266ef07598.jpg

Chests = Shards (skins, champions, icons, wards as materials)

3 shards = 1 random permanent item from those 3 shards

Shards = Essences when you disenchant them

Essences = 1 permanent craft (you need the shard tho)

There are champions essences and cosmetic essences, not the same use

You can craft champions, skins, wards, icons