I usually go for the Lancer, White mage, Black Mage and Ninja. But other times I go with Knight, white Mage, Hunter and Geomancer as the hunter and Geomancer jobs (imo) make the game harder because they're so ****
I'm not entirely sure. It's been so long since I played a game where I didn't master as many jobs as possible as early on as possible that my memory of what strategies I used is rather cloudy. I pretty much always had one white mage and one black mage, though.
i personally get the highest white magic as soon as possible then switch to black and max that...that way i wont be limited to red magic later when i switch to a different job. Then i have a monk as my attacker and i level him up just until he learns barefist, then switch him to berserker...my third character does nothing until i get the summoner and time mage jobs from the second crystal, i alternate with every job level up so i can keep my berserker nice and fast and my party nice and healthy with sylph summons. nothing too special about my fourth character except that he can do anything the others do because he's a mime...what works for me won't always work for you though.