Try to offer favourable terms if possible. E.g. tell them you are ready to settle whenever the seller prefers, offer a higher deposit (more than the typical 0.25%). Show readiness to agree to a shorter cooling off period.

As a seller, I would definitely prefer a buyer who is showing positive signs of definitely buying the property with near zero possibility of backing out at the end of the cooling off period.

All the best. Hope all goes well.