If you're looking for a female, just for sex... it might interest you to know that most girls/ women want to have a "relationship" with a man before becoming his sex partner.
Many guys feel troubled by this question. It used to be one of the most difficult and painful questions which I had to ask myself when I couldn´t find any partner for sex or relationship or both... The situation is more complicated for shy, not socially dominant, not very successful or self-confident guys or for guys who are very sensitive and not very experienced. Moreover, in spite of all the social changes it is still usually expected that the guy will be the person who will initiate "the first step", who will come with some kind of "offer" or "interest" and the girl will decide whether she accepts or refuses the offer.
There is a wide range of non-verbal signal of body language which may contribute to our success or failure in this area - most of them do not even operate in a conscious level of our mind.
Be careful - if you send some direct or indirect/subliminal messages that you really "crave" for sex too much, that you are desperate to find a (sex) partner - it usually has exactly the OPPOSITE effect on girls. It is important not only to show YOUR desire but it is equally or even more important to "create" HER desire for you. And this is a mystery...
The only advice I could think of is:
-try to be self-confident.... be aware of your strength as well as your weaknesses and try to present your strong points and search for contacts with specific girls who would be likely to appreciate your qualities. (e.g. if I am very bad at sports and I am not physically super-fit, I will not waste my time and energy trying to make an impression on some girls in a sports club, but I can try my luck in some music festivals for example...)
-try to have as many contacts with DIFFERENT groups of people as possible and try to find a suitable strategy how to get closer to some girls there. Of course, if you feel that some girls might be interested in you, do not be too "picky" and do not refuse the girl who shows interest in you just because she is not 105 per cent perfect girl of your dreams.