Well, when writing an office romance novel, it's important to make the office setting feel real. You can do this by describing the cubicles, the meeting rooms, and the daily office routines. For the characters, give them unique personalities. One could be a workaholic, the other a laid - back type. Have them interact in different ways, like arguing over a work decision which later turns into a flirting session. Don't forget to include some emotional depth, like one character having trust issues from a past relationship that affects their new office romance. And use dialogue that is both professional and flirty to bring out the office romance feel.
To write an office romance novel, you need to understand the workplace dynamics. Research different office cultures and hierarchies. Start with a great hook, maybe a new employee starting on a chaotic day at the office. Develop the characters' backstories, especially how their pasts affect their present in the office and their relationships. Show the small moments of connection between them, like sharing a coffee break or working late together. Also, add some external factors that can either bring them closer or create obstacles, such as office gossip or a big project deadline.