Teshuvah (repentance/return) begins with recognizing one's wrongs, and feeling sincere remorse. Saying or texting to people (or posting on FB) "If I have done anything to offend you this past year, please forgive me" doesn't cut it. You can't ask forgiveness if you don't know what you did wrong, or even IF you did something hurtful. Be specific in your requests for forgiveness. No one deserves a generic "form letter" apology, and it doesn't help you grow as a person either.
Yes, I know I wrote about this before, and it's worth reading again (or for the first time). It's important enough to me that it made it into my second book too.