Thanks for your comments here. I tried all these tactics (believe me) but I guess I need to practise some more.
I tried the "hold back and pick them off as they come" tactic but going up against Class 3 or Class 4 stations is a pain since they manufacture Cruisers and TIEs easily to throw at you. In addition I can't seem to lure Imperial fleet away from the base. They will go back to guarding the base after pursuing you for a short distance. So that doesn't work.
I tried the fighters and bombers tactic but their Tartans decimate my flights before they could reach the base. No use using frigates to take out the Tartans first as the base will resupply everytime one gets destroyed.
The only thing I can think of is holding back and using missile frigates to blast the base. But then you need to be able to see the base first. That is tough unless you send in the Sundered Heart to fly around like a mad chicken attracting enemy fire.
Tough. So I take out the ground first before attacking space.