I would think of somewhere you went on the first couple of dates, like a particularly city or just a restaurant. Re-visit, but make it better. Stay overnight in a nice hotel this time, or book something he's always wanted to do, but remind him of the early days by wearing a certain item of clothing or perfume. Certain smells definitely remind me and my hubby of our first date, or honeymoon and stuff. Why don't you meet at the venue, instead of travelling there together? You don't have to go full-on role play and pretend you're strangers, but it does make it more exciting, the anticipation. Then do something you never would normally, like.. well you have a think!