I use Vipassana technique, which is mindfulness. I watch the breath, awareness on the breath and the sensations I can feel within the body. You can never stop thoughts from happening. The very act or intention of stopping thoughts is in itself creating another thought. Mindfulness meditation is simply watching thoughts without becoming attached to them.
Sure, when sitting for meditation, after 20 seconds of watching my breath (eg, feeling the sensations the breath makes on the nostrils as I inhale and exhale - on the inhale, the breath is slightly colder, and on the exhale the breath is warmer), a thought randomly pops in, "I must buy some broccli", "how could she say that to me, grr"... and any other random thoughts also pop into my head at lightning speed. Instead of allowing my awareness to follow each train of thought, as soon as I become aware that I've followed the thought, I gently and lovingly bring my awareness back to the breath. It's a constant practice that gets better with time, patience and love.
I have tried all sorts of techniques - mantra chanting (silent and out loud), mala bead counting, visualisation but I've found this technique - mindfulness - to be the best and most profound at really getting to the core of what its all about and finding a true self-acceptance. Accepting life as it is which includes accepting the mind as it is without trying to alter it. Just observing the mind without attachment to the thoughts.