Not sure if this is the right place for a makeover since I didn't actually build Twinbrook, but here goes ...
Because I replaced several single function buildings with combo buildings several lots were freed up. I also removed all Showtime venue lots, the fire station, the tattoo parlor/salon and bulldozed the large junk yard. This freed up a lot more lots. Whenever I want to play one of the Showtime careers there are plenty of lots available.
central park and city government building (city hall/police and military)
school and sports
grocery/cafe combo with bookstore/spa combo
I built a larger gym where the fire station used to be. It has a large pool with 2 diving boards, 2 hot tubs, a sauna/steam room, a massage table, a dance studio, a sim fu room and bathrooms with showers downstairs. Upstairs is a tread mill room, a weight bench room, bathrooms with showers and a snack area.
I placed a small consignment shop where the old gym used to be
I put a criminal rabbithole rug upstairs in the laundromat
I placed a movie theater with two big movie screen rooms and the film backlot where the old consignment shop used to be.
Redid the Red Rendezvous to include a dance floor and a karaoke machine, etc.
Placed a university hangout where the old spa used to be. It has bowling, pool and ping-pong.
Placed the plum Klub, an adult and/or vampire lounge, where the old diner used to be.
I may place the tattoo parlor/ salon on its original lot and place a 20X30 firestation on the old theater lot next to it.