It depends on the Sims who are dating.
I like for my Sims to do activities and so I'll have my Sim who is dating one who likes music (for example) to tour the Music Hall or some other venue. Or, I'll send them to the library if one has the bookworm trait. Sometimes, I'll pack a ball in my Sim inventory and send them out for a date at the park. The park is fun because there are always other Sims for both to interact with and it never get boring.
There's also usually a chess table for them to engage in a game of chess. Then, I may conclude the date by having a candle light picnic in the park or roasting food over the fire pit. If my Sim really likes the other, sometimes I'll have them prepare a group serving of that Sims favorite meal and find a good picnic table and 'call them to meal'. I also (using the 'go here with date' option) always have my Sims drive their dates home (by clicking the sidewalk outside of their house) before ending the date.