If you are a Premium Member in Cabal then you are able to use these dummies. Every city has its own 4 dummies (they stand next to the city - often outside of the town). You can train up to 30% of your Skill Rank at those dummies (after reaching level 90 there is another way to skill up at dummies.

To skill afk (away from keyboard) there are 2 hints:

The Press-Down-Your-Button-All-The-Time-Hint:

Just put a coin or a sheet of paper between the skill buttons (you should add your skills to your quickslotbar before).

The Window-Mode-Hint:

At first you switch in window mode (Options - Graphic - Activate Window Mode). Then you target the dummy and press the quickslot button for your skill. Press the button all the time, so that your char casts nonstop. While pressing the button, (goldceo.com)click outside of the window (for example at the desktop or at the toolbar). Now stop pressing the button and your char should cast nonstop without pressing a button! It's important that you don't minimize the window (otherwise it will abort)!

Ingame Shop Hint:

Just press the button again like at the Window-Mode-Hint and while pressing it hit the ingameshop button (little coin at the right bottom of your toolbar).

PRO You can be afk; 1/3 of the rank can be trained

CONTRA It takes a long time because you gain less xp then with the other methods; limited to 30% of the rank (except you are level 90+ and did the rank up quest); you have to be a premium member;

Like mentioned before we are now able to skill at dummies beyond 30%. The mean thing is that you have to be 90+, did the level 90 rank up quest and own a premium account. If you have these things then you are able to level nonstop at those little dumb puppets without being at the PC. But there is a little thing which has to get mentioned:

After you passed 30% of your rank up (example: 30 of 90 ups) then you get less skill xp as before! So skilling up needs more time after the 30% (but of course you can continue)!

PRO No dumb skill farming anymore; you can skill up afk; nonstop skilling without interruption.

Well, I'd like to recommend you buying the cheapest Cabal gold and Cabal powerleveling from Goldceo. Just have try!