Lockpicking
There are self locking chests now on the roof of Insula Bank to train your lockpicking skill, complete with lockpicks!

You can gain to 100 from these chests. Thank you IndianaMom for confirming this.

Note: You can gain off of the same crafted box repeatedly by re-locking it.

0 - 30: Train at NPC Thief or Tinker.
30 - 55: Pick locked boxes made by 30 skill Tinkerer.
55 - 70: Pick locked boxes made by 50 skill Tinkerer.
70 - 88: Pick locked boxes made by 70 skill Tinkerer.
70 - 95: Pick locked boxes made by 100 skill Tinkerer.

After 95 skill there are 2 different ways to reach Grandmaster.

Method 1: Pick level 4 treasure chests in dungeons or do level 4 Treasure Maps.
Method 2: Satyr Trick

Sherlock lockpicking quest for 120 lockpicking

Step 1: Pay a visit to Sherlock either in Bucs Den in Felucca ( North-West of Moongate ) or The Underworld in Ter-Mur ( Most North-West room ) He Will ask you for "A Rare Pandorian Diamond (10 Karats)" These can be got from any level 6 treasure chest. You can set out on the hunt for one of these before starting the quest. They can also be bought from other player as well.

Step 2: Talk to Sherlock again after turning in the diamond. This time he will ask you to fish him up 2 "Mud Puppys". These take minimum 80.0 fishing skill to catch. It has been said these can be found any where in the world. But the best place to fish for them is the river in the Underground.

Step 3: Talk to Sherlock once again. This time he will be asking for 1,000 "Polar Bears Skins". These can be found on the corpse's of polar bears. You can set out the hunt for these before reaching this step. It will take killing ruffly 700-1,000 polar to collect them all. They can also be bought from other player as well.\\