The story focuses on the ways that romantic attentions, both wanted and unwanted, can get tangled up with workplace and professional responsibilities. It sets up a lot of possibilities, though much of the time the script settles for light humor rather than trying to get more out of a given scene. It does work well enough as a light romantic comedy, and indeed many other movies over the years have had the same options and have made the same choices.
Hedy Lamarr gives the best performance, as a psychiatrist/author whose professional and personal feelings become intertwined. Her character is interesting, and it's a little unfortunate that her dialogue was not written more carefully. But she does quite well with what she has to work with. Anna Sten works well as an amorous cosmetics tycoon. Robert Cummings is believable and likable as an advertising executive, although he sometimes portrays his character as a bit too much of a bungler. Robert Shayne is adequate, though often rather dull, as the fourth of the major characters.
Overall, "Let's Live a Little" is a decent movie to watch as light entertainment when you don't want to think too much. Its low-budget look and its general avoidance of the more interesting possibilities keep it from being much more, but a movie like this can be worth watching if your expectations aren't too high.