If you did it (almost) perfect it’ll look like this:

Note that there is always some range of tolerance where you can hit before the 1st line and it’s still ok. And you can ALWAYS hit behind the 2nd line and it’s ok.

How is your combo-ing now?
…ya, right. Go cry you sissy!

Maybe it’s time to find an experienced mentor for you, and I have an idea who could be your mentor already.

With an armour like that he won’t have to prove his experience to anyone.

Now sit still and let him have a look your setup of skills.

As you can see he has 3 skills already, but he didn’t listen when I talked about cast- and CD times. The first 2 skills' cast times add up to 3.1seconds and that’s less than the 3.6seconds CDT of the 3rd skill. It can’t work like that. Once Power Stab is at lvl 3 it’ll have a CDT of 3.0seconds. Everything fits then.

At lvl 9 a skill's cast time will equal it's CDT, at least up to the Master skills. After that it may vary. To find out how many seconds of CDT a skill loses per lvl you need to subtract the cast time from lvl 1’s CDT and divide it by 8.
Example: Power Stab (see pic above) has a cast time of 2.0secs and a CDT of 3.6secs.
3.6 – 2.0 = 1.6; 1.6 / 8 = 0.2
At lvl 10 the CDT will jump up again to start falling from lvl 11-18, but it won’t ever reach the state where cast time = CDT again. Lvl 19 and 20 I haven’t analyzed so far. I may add that later or search the forums. I think they are stated somewhere.

The mentor surely knows what he’s talking about. He teaches our little loser another vital fact about combos. Focus multitasking – the ability to fight a monster while focusing on another.
He tries to listen carefully, but as a warrior he’s not one of the smart guys. –Big buffs, no brains!-

Focus Multitasking: First you need to find out how many hits you need to kill a monster. (preferably the number of different skills in your combo, or a multiple of that) Make sure it’s not going to die in less than the expected number of hits if one of the skills hits critical. YOU DON’T HAVE TIME TO WATCH THE HP BAR! When the last skill starts you should have found a suitable next victim and select it so the next skill can hit that one while the previous monster dies. That’s what we mean by ‘Focus Multitasking’. It’s not always easy to watch the Combo Gauge and also look for a new monster to kill and sometimes you’ll even have to spin your view around a bit – that’s when it comes to practising. You can make it easier for you if you choose the skill with the longest cast time to be the final strike.