What is the most effective way to prevent or blunt regular migraines?

Depends on patient. Sorry. There is no answer for everyone. Different treatments are effective for different patients. Unfortunately up to one third of patients don't have any effective treatment.
First, no triggers. The ideal preventative is to identify a reliable trigger that is setting off your migraines, and then avoid it (common triggers include food containing tyramine (e.g. Aged cheese), red wine, sleep deprivation, and stress). Barring that, there are many medications that reduce migraine intensity and frequency, as well as procedures such as Botox for refractory cases. Neurologists can help guide you.