To effectively work Faction Standings for all non-pirate Factions, Complete each of the following:

Tutorial Career Agents
Sisters of Eve Epic Arc
Circle Agents
Data Center Agents
COSMOS Agents
Epic ARC Agents

The order above is read as the most likely achieved first, then the next likely achieved. It can be tailored to your individual needs.

The Circle Agents need a fast Frigate with 100m3 cargo space.

The Data Center Agents only need a shuttle but will get quite expensive real fast due to tag costs.

Between The Data Center & COSMOS Agents, you will need to grind Faction standings to access the higher Epic ARC Agents.

The best 2 Factions to work this - for a balanced approach in gains - are Servant Sisters of EVE and Caldari State as these have the highest Faction gains with the least amount of losses and will hold Minmatar at 4.

You will be working the see-saw effect from here on, so choose your Agents wisely.

Hope this helps....Good Luck & Fly Safe!!