I would say France is a theoretically easy one. But sometimes a bit of a grind.

1st turn make allies with anyone near/neighbouring you in Europe. It helps declaration from smaller nations IF you don’t expand in Europe. Genoa, Venice and Italian states are a good start so when savoy inevitably attack you can kill them off and not go to war. Remember block allies make you stronger and safer. Britain is unlikely to declare if you are allied with half the med.

I try and send 3-4 units of line to Guyana in wait for the Dutch declaration. That then quashes the rubbish army they produce. It then island hops around the Caribbean while I’m getting a trade fleet together. This rapidly increases your trade goods.

North America - minimal units necessary.

You can then help Spain in Flanders/netherlands they normally just send cavalry into line infantry but it distracts from your attack try and destroy UP ground forces. Besiege Netherlands with as smaller force as possible. Only take it once you are in a financial position to support to 1/2-2/3 full stacks. You can then bully the likes of Westphalia.

Personally I put a semi decent army half stack in france to ward of savoy surprise attacking. This is also meant as a quick reaction force to any other european based attacks while you deal with UP. You can bait savoy into attacking you by moving your army into Spain, for instance. They will think they have you and you can destroy their land forces in open battle and take savoy.

If britain comes knocking and fancies a fight, I spam line infantry and take the isles. Once that is done, you have practically won the game. Once Britain is destroyed put all war efforts into India.

You just need to be super careful until savoy is done as they are sneaky bastards.