Engagement party gift ideas please

[lovelynannytobe]

I have been invited to an engagement party. As I have never had one myself, never been to one and not from round here I have no idea what the done deal is here. Would it be out of place to put some money in a card? I don't really want to buy any trinkets with their names/initials as I hate this type of stuff myself. Any other ideas?
I will be invited to the wedding too.

Just a nice bottle of champers will go down a treat I bet. Or cava/prosecco in a decorative looking bottle, they often have a good selection in supermarkets (Waitrose especially).