A common sense approach.
Make sure the dog is well exercised before dark and has had every opportunity to empty bowel and bladder. Do not turn him out into the garden once fireworks have started unless absolutely necessary, then not alone and preferably safely on the lead with you supervising in case he panics and runs away.
A fearful dog may not consider eating so adjust meal times to take account of this, a full tummy may make him more relaxed.
Do not take the dog to a firework display in the hope that they will learn to enjoy the experience, this is unlikely to work.
Preparation.
Provide a safe haven, a den, for example a covered cage, a cupboard or cardboard box, site it somewhere dark and secure, but make sure the dog is used to the space well in advance - let the dog help you decide where this might be. Some dogs will try to hide in the most unusual places- open cupboards, even under the bath- if this keeps them feeling secure. Why no allow it at especially stressful times?
Make the area comfortable with the dog’s normal bedding, add favourite toys and provide water but leave him free to choose whether to stay there or seek your company – he may be calmed by sticking to his normal routine of resting by your feet while you watch TV! If you are at the computer or reading play some background music to mask the sound of fireworks.
Close curtains and blinds as soon as it falls dark to keep out light flashes and muffle noises.
Remember to leave your dog wearing his collar and identification tags just in case the worst happens and he escapes in panic.
Occupy your dogs brain by teaching him a new trick or brushing up on old ones. Divert his attention by playing with a favourite toy or providing him with a new treat or chew, maybe stuff and freeze a “Kong” type toy with special tit bits to prolong the reward.
Avoid leaving your dog alone if possible . Remember a frightened dog is not rational.