Romance involving a maid character can feel clichéd if you rely too much on the 'servant falls for the master' trope, so I'd suggest digging into her motivations beyond just duty. What makes her choose service as a profession? Maybe she’s supporting a family, hiding from a past, or genuinely finds pride in her work. The romance should challenge her worldview—like a master who treats her as an equal, or a fellow servant who sees her struggles.
Physical intimacy can be tricky—avoid making it feel exploitative. Small gestures, like noticing her exhaustion and brewing tea for her instead, carry more weight than grand declarations. If you want tension, consider class differences realistically: would her family approve? Would his? 'Downton Abbey' did this well with Anna and Mr. Bates—their love was quiet but fierce, built on mutual respect.