How do you sharpen your knife?

I use a wet stone on my knives and wood chisels.

if they are very dull, I like a fine file to get it in shape then a couple stokes with the rod

I've been advised to not handle sharp objects, but use a 3 stage electric and a steel for kitchen knives. File for axe/hatchet, and stone for outdoor knives.

Dry stone, then wet stone with some gun oil then I use sand paper to finish it.

I prefer my wet stone.

I use a small 1 inch belt sander with an angle guide on it. Grits I use depend on how dull the blade is. For just touch up I use a 1000 grit belt with about 5 passes on each side. I then stop it on a ceramic rod. Takes a little while to get the knack of doing it. I started out with 2 junk knives until I got a feel for it. In the field I use a small diamond encrusted steel rod. Worksharp has some nice little ones you can carry in your kit also.

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I Think I'd Sharpen Mine On The Skull Of The Victim I'd Just Stabbed To Death.
Then Steal His Knife In Hopes It's Sharper Than The One He Was Stabbed With.
"Strategic Planning", That Should Work Out Fine.!

I buy new ones

It depends on the knife. For my kitchen knives I use a diamond steel rod, for others, and especially my daily carry - my Crikt - I use whetstones with a final finish on an Arkansas Surgical Black stone. I also used very VERY high end natural stones for my straight razors.