How to sharpen European style kitchen knife (Double-ground edge)
Keep the constant angle between whetstone and blade.
Spread wet cloth on sink, and set whetstone which you dipped into water enough on wet cloth. Place blade aslant at an angle of 50° on whetstone.
Keep the constant angle for 3 coins between whetstone and blade. (Please change 2 or 4 coins depending on the condition of kitchen knife.)
Do not press blade hard by finger-tips.
When you sharpen front side of kitchen knife, you hold it like the right picture.
Place 3 fingertips of left hand on blade, without pressing hard and sharpen rhythmically until metal burr at cutting edge feels rough to fingertips. Then slide blade to the next partition and sharpen whole part of the blade properly.
Sharpen blade in 4 partitions. Do not sharpen whole blade at the same time.
Divide blade in 4 partitions and sharpen each partition form down part of blade to tip, or vice versa, by sliding blade on whetstone.
Sharpen back side of blade by less force than front side.
After you finish sharpen front side, hold knife as picture to sharpen back side in 4 partitions. Sharpen until metal burr on front side feels rough to fingertips. Keep the constant angle for 2 coins between whetstone and blade. (Lay down just a little than front side.)
Finish by wood stand of whetstone.
Place cutting edge on bottom of wood stand and pull knife toward you to take away metal burr.
Finally wash kitchen knife with water and wipe blade and handle enough with dry cloth.