Hi Lyndsey. Formal-casual, or what some lines call semi-formal or informal (as opposed to casual), covers a wide range. To help narrow it down, one guideline is to wear what you'd wear to a wedding or nice church service.
For example, I'm leaving for a cruise tomorrow, and this is what I've packed for those non-formal evenings. (Keep in mind that I'm early 40s.)
- Floral skirt, turquoise short-sleeved knit top, and low-heeled tan pumps (can't forget the shoes!)
- Dark blue pantsuit (jacket and pants), yellow knit top, and those same low-heeled pumps
- Dark red/black poly-mix tank, matching jacket, black pants, low-heeled black pumps[/list]This is in addition to the sequined black dress for formal night and sundresses for the casual nights.
These are just ideas, and there are no hard-and-fast rules. EXCEPT -- make sure your shoes are comfortable.
Enjoy shopping... that's my favorite part leading up to the cruise!