I don't dry fire my guns just to smooth the trigger, as I don't believe it truly makes a significant improvement (there is some improvement, but not much), IMO. I do dry fire practice to reinforce marksmanship techniques as well as practicing defensive skills that I might not be able to use with live ammo at a range (i.e., one-handed reloads, awkward positions, etc.). When I do dry fire practice, I always use snap caps.

As someone who has broken the hammer nose on a S&W revolver from dry firing without snap caps, I can tell you I don't do any extensive dry fire practice without them. It's cheap insurance, even if the newer guns aren't as susceptible to such damage.

Plus, if you get a couple sets of them, you can practice reloading skills.

FWIW, my favorite snap caps are A-Zoom brand.