There are so many things that I could say this about, but I'm talking about spells and rituals and every other aspect of Witchcraft. I hear people say they don't want a specific deity as their Matron or Patron because of what they've heard about that deity. For example, I was terrified when Cerridwen (and later Hecate) "called" to me because I knew they were considered Crones and I heard all sorts of BS about them. People told me that because I'm young I couldn't have a Crone as my deity, and that they were "evil" basically because they're Crones. I was also told that they just couldn't be Matron deities with no explanation for why. (At some point in the future, after some more researching, I'm going to post about Hecate, possibly in several posts. For the record, she is NOT a crone!)
As for spells and rituals, stop being afraid of screwing something up! Intention is everything. Learn to laugh when you say something wrong, or call the east quarter for the south or whatever. Trust me, the gods and spirits have senses of humor. They aren't overly serious and you shouldn't worry about being that way, either. The serious stuff is important, but having fun and actually enjoying what you're doing and feeling a connection to it is more important. You have to enjoy what you're doing and feel connected to it! That's what makes it work for you. You can't just read something from a book every time with no feeling and expect your spiritual life to grow or to get results from what you did.
Oh and the taboo subject of spells that some view as "negative." YOU make your own rules, YOU know what feels right to YOU, etc., so no one else can tell you what to do or what not to do. If you really need someone out of your life and you've done all you can in the mundane sense, doing a spell to cut ties with them is a good way to go. I don't necessarily agree with doing spells that could harm someone, but think of this scenario: You're a mother and you find out that your daughter was raped by someone and she didn't know them and they haven't been caught. Is it wrong to do a spell that would cause something to happen to them that would lead to them getting caught? I read a journal by someone who did a spell because her daughter was nearly abducted. She worked it so that the person would have something happen to them that would attract the attention of cops. Some time after that, the guy was cruising around the area again and tried to abduct another child and he developed a genital itch. Some cops happened to be nearby, saw the suspicious activity, and took the guy in (I think maybe he was a sex offender, not sure though).