While there are a couple of comics who do the 'jump scare' thing well with a comic format and a bit of coding trickery (the Bongcheon-Dong Ghost), I think the best way to approach horror in a comic is to throw the idea of the typical horror MOVIE out the window, because it doesn't really work with a horror comic. (Heck, often times I don't think it works in movies either...)
Mystery, slow build up, unnerving situations, and character behaviors, high atmosphere, disturbing imagery, that stuff has to be the focus. It's better to make it more psychological than in your face.
Sometimes I think one problem with horror comics is their main focus is trying to scare you and they forget to tell a proper story with it, which makes it less scary. XP
I don't usually like 'gore for the sake of gore' comics, even the bloodiest comics I follow usually have something else going for it, often times they aren't even exactly horror stories. Rarely do I think horror comics that rely solely on gore or gross imagery alone do it well, or if it does it's usually a black comedy. If violence is the 'horror' part then you REALLY have to make it unexpected and make it really punch, and even then it's better not to rely just on that for scares.
But yes, I LIKE horror, but I'm very picky about it. XD There are actually very few straight-up horror comics I can name that I like, or the ones I can name really just have elements of horror that was done well, but they aren't 100% horror.