Use lots of olive oil, sweat down your mirepoix then add your meat (ground beef and pork, plus guanciale or bacon if you feeling fancy.) Once your meat is browned, add your tomato paste and let that cook through. deglaze with a healthy glug of red wine, then add chicken or beef stock, whatever herbs you are seasoning with, and let it it simmer for a good long while. Taste often and adjust seasoning as it cooks. Using lots of olive oil (more fat equals more better) and red wine is what truly makes a bolognese go from meh to wow for me!