Humblebragging is a bad communication approach for liking. Don't disguise a brag or accomplishment beneath a casual phrase.
If possible, avoid overseriousness. Of course, you must work hard and treat relationships seriously.
Disengagement is another bad habit. Probably apparent, but nobody loves being ignored in a conversation.
Poor emotional intelligence also turns people off. In fact, emotionally inept people are hard to get along with.
Name-dropping, or naming someone prominent or famous, is another unappealing behavior that may be easier to eliminate.
Many of us propagate rumors, another bad habit. Many people talk about others to connect.
Opening up to loved ones and being vulnerable is fine, but you must first build trust.