Others more experienced than I may give better advice, but here's my 2 cents: Trick I learned from Wayne Goddard to get an even bluing (not blotchy) - mix a 3 oz bottle of something like Birchwood/Casey Super Blue in a gallon or two of water and dunk your blade in that for awhile rather than wiping straight bluing onto the blade. Trick I learned from a family friend - dunk your blade in a mild etchant and rinse that off before bluing to get better/smoother treatment. So my current method: Clean the blade to remove ANY hand oils using acetone. (1) Dunk it in a light solution of Ferric Chloride - I don't know the exact mix, but a chunk of 5160 dunked in for 40 minutes gives me an even black surface without undue erosion of the steel - then spray wash (2) dunk it in the above mentioned solution of bluing and water for 40 minutes - then spray wash (3) repeat 1 and 2 twice so you have 3 complete cycles. Timing will vary depending on ambient temperature and strength of your solutions. 3 complete cycles give me a good durable coating, but it will not prevent rust - just slow it down enough to make a knife easy to care for. Oil or silicon spray is retained well by this surface - but the sharpened edge is still unprotected bare steel and will rust according to the nature of the steel composition.