Accumulate is great. Its not cheap, its there for the player to use so use it.
First and foremost I gain enough money to buy characters with the name I want and with good faith/brave for the jobs they will be doing. Most of the time as you know the default characters suck the big ens.
What I usually do to power up my characters is to first master everyone at squire first, and even most of the time let them become level 8 squires.
After they master squire, I take them make one an archer, two a knight, one chemist, and one a black mage. I always fight at the Mandilia Plains, with the two knights on the front row with the archer in between them, the chemist behind Ramza on the right (looking at the party with the edge of the map in the back) and the black mage to the left of the chemist. This set up always works, and if you keep Accumulateting you can power up and become bringers of death, destruction, and total chaos in no time.