definitely try it out with some less important blades first. practice is what will get you the results you want.

whenever i feel a bit rusty or unsure on the belt, i bring the kitchen knives over and run through them 'til i like what i see.

i rarely let my knives go too dull, usually start with a 400 grit and work my way up to 1000 in increments of 200 or so.