Depends on where I am. Generally nothing special, and I've rarely gone to NYE parties.
I remember once my wife and I were on vacation overseas and I had even packed a bottle of Moët. We just had whatever the package tour had for dinner that day. I asked for a bucket of ice from the hotel, and they did have them, but it was tiny and nowhere near big enough for a bottle of Champagne. I kind of got it cold, although my wife didn't feel like staying up and I was the only one drinking that. But the city we were in did have fireworks at midnight.
One NYE we spent at
Disneyland, but went back for a break and had dinner near our hotel in Buena Park. It was pretty nice, but nothing different than what we might have had at other times during our visit. Then we headed to Disneyland after dinner, and it was absolutely packed with DJs, laser lights, etc. We went through California Adventure and Disneyland Park (where we saw the countdown). I might have mentioned it, but I was feeling pretty sick and we spent the next day mostly in the hotel room other than a little errand I needed to do (get a rental car flat tire replaced).
I was at NYE alone last year in Anaheim with my family visiting somewhere else. Dinner was at the Anaheim Packing House, but I headed to Disneyland for NYE festivities. Kind of a letdown since it was raining buckets and they didn't have fireworks - just a light show in the rain.