Refining!
This is quite possibly a common area in which people lack and have no idea just how much it can improve your character
With the right refines, you can increase your most important stats and it can mean an extra 5k hp, or 2k defense or 1k attack or more.
So let's start looking at refinig equipment and what you should aim for!
Firstly you need attack. So your highest priority should be to obtain both +Strength and +Patk
Once you have these two, as a knight your next best choice is +Armor or +Defense. (They are the same thing, it will show as +Armor on PVE equipment and +Defense on PVP equipment
That's 3 down, now your 4th best choice is Block. It'll give a good amount of block compared to gems.
Final refine now, is +Endurance.
If you're not able to afford Balens, then I would try grab the first 3. Once you've achieved this, it'll provided some good attack and defenes If you can afford Balens, then by all means go for it. Lock in those stats and get those 5 refines.
Now, just so you know what you are getting, below is what the refined stats will provide;
+1 Strength = +4 Patk and 1 Pdef
+1 Armor/Defense = +4 Mdef and +4 Pdef
+1 Endurance = +20 HP
The others should be pretty self explainatory, +1 Block = +1 Block and so on.
I have provided a screenshot to show exactly what you want.
Now as for the level next to the refined stats in brackets, that is basically the quality. The higher level it is, the more stats that refine will give. This cannot be leveled up.
When refining you will be given a random attribute ranging from Lv 1 to Lv 10, So in conclusion, getting +30 Defense would amount to +120 Pdef AND Mdef, which you would normally get +120 Pdef OR +120 Mdef. Obvious choice is to get +Defense to get 2 in 1.