Being sexy in summer can be quite difficult, in the winter there is the option of blacks and deep red, which alone give a hint of sexiness, however in the summer there are pastels, creams and nude colours, being girly is seen more than being sexy or sophisticated, so ive set myself the challenge of finding ways to turn subtle into sophisticated.
Generally if i want to follow the "sexy not slutty" handbook i go by the 40% rule, only show 40% of bare flesh, legs or arms, not both, back and from the knees down or cleavage mixed with from the elbows down and just above the knees hem line, i find this works a charm as you wont be bothered by the men "out on the pull" but the men who came out for fun with their mates, and its always a sign when they ditch what they are doing to come over and talk to you.
For day time i would suggest a maxi dress, as with revealing clothes it draws attention to you but the people looking wont be thinking "oh dear lord wheres the other half of her outfit" but "wow she looks good" i cant explain why people do but its a fact that wearing long dresses draws the eye in. i would wear a plain or tribal patterned maxi with either wedges, clogs, ankle boots (generally a thicker heel to balance out the length of the dress) or if i was wearing flats brightly coloured pumps or vibrant sandals with an anklet. As seen in Phillip Lim