i honestly believe it helps to be a bit of a mixture, perhaps leaning slightly more towards sexy, but having elements of cuteness is not a bad trait. it allows girls to open up to you easier.
being sexy is all about your fundamentals and your vibe.
look sexy, talk sexy, smell sexy, feel sexy - combined with sexy body language. when it comes to the body language consider;
eye contact, stillness, move in closer, touch.
you must also exercise the traits of a sexy dominant man. move fast, control frames, persistence.
this is a very big subject and i could talk all day. but there are some of the fundamentals to get you started. but honestly chase covers the 'sexiness' element very well on the girlschase website, better than i or anyone on this forum could, so keep reading.