Basically, trying to answer the question "What does a typical Imperial/Rebel task force look like?" Here's my stab at it, please interject with what you use in your campaign!
On the Imperial side, I would expect
1+ Imperial Star Destroyers, serving as flagship. More may be involved if it's a matter of huge importance or opposition is expected to be large.
1-3 Victory Star Destroyers. In the Outer Rim or less-supported sector fleets, some of these may be supplanted by aging Dreadnoughts.
0-1 Interdictors. Depending on the mission of the fleet, one of these may be necessary. Again, less supplied fleets may have to do without.
1-2 Escort carriers with a full complement of TIEs
4-8 misc craft: Nebulon B frigates, lancers, Carrack and Strike cruisers, etc. There would probably be no more than 7 total of these, no more than 2 repeats.
Fighters would be a full complement of TIEs. Craft capable of carrying a full wing will include TIE/in and bombers. Depending on era, you may see some gunboats or TIE Advanced in the mix.
For the Rebels, we have
1 Mon Cal MC80a star cruiser, acting flagship. Unlikely to have more given Rebel resources, unless it's a major attack or you're running a setting where the Rebels have more fleet strength available to them.
1-2 Mon Cal MC40a light star cruisers. If no MC80 is available, one of these will likely be serving as flagship.
0-2 Alliance retro-fitted Dreadnoughts
0-3 Bulk Cruisers (depending how underfunded this particular task force is)
1-2 Nebulon B frigates
2-4 corvettes and gunships of Corellian make
Fighters would be primarily Y-wings and X-wings with some A-Wing support. Z-95s may be kept on hand for low-profile missions, posing as mercenary craft. B-wings will be included in larger task forces.
