I have watched many of these types, and they are usually great. I'm looking for more, hopefully somebody can help.
Coffee Prince is most famous, then I like Arsenal Military Academy, also My Unicorn Girl. IMO those are very strong in what I'm looking for.
The main theme is the FL is cross-dressing, and it's a very strong thing throughout the drama, not just the occasional dress-up because she's going to the market, but it's a important aspect of the character.
And also romance with the ML.
But it doesn't have to be cross-dressing, a tomboy aspect is good too, like Secret Garden, FL is very tomboyish there.