Hi, it depends clearly of the scenario played.
If French are waiting for Bayonet Charge, it gives time to the British side to strenghten its hand (especially if you are playing with the Tactic cards and defending).
Use the Artillery to weaken the Infantry in LoS (33% per die of inflicting a loss).
Occupy hills, forests and towns to weaken Infantry melee power.
Do not forget to support your own units to avoid retreat and make battle back more probable.
Play your Recon and weak cards at the beginning of the game.