Love and logic: offer choices.
"Do you want your pink shoes or your brown shoes?"
Only offer a choice you are ok with. "Do you want these shoes or are you going barefoot?"
Offering the behavior you are unhappy about, as an option, is confusing to anyone, especially a child.
Threats: follow through.
Only make threats you are willing to carry out.
"If you don't stop kicking me I am going to leave."
"If you don't eat this sandwich, I will."
Kids need to be taught boundaries. If they are given options that are not really an option, that is confusing. If they are told there will be consequences but there never are how are they to learn to obey? And how are they going to develop a sense of boundaries for themselves in relation to others? Kids push the boundaries like leaning on a wall. It reassures them that it doesn't move.