These are some of the steps which are gonna help u a lot fore more you can go for the link above and below........see u there :)
Make sure this person is someone you're really interested in and someone who's worth your time! Make sure there's a mutual spark.
Tell the person up front, before things start getting hot and heavy, where you stand and how far you are willing to go with him/her. Remember that sex must always be consensual and if you're saying no in the first place, this person should respect that. Hopefully, once you let them know, they won't even try to go further than you're comfy with.
Realistically, however, even if you start a casual make out session with "Hey, look, I don't want to have sex with you", the person will probably try to take it further. Especially if this someone is a guy. So be prepared to stick by what you said before. Do not budge just because they're begging or looking at you a certain way. DO NOT BE PERSUADED. If the person is getting annoying about it, stop whatever you're doing and firmly tell him/her that if he/she can't respect your decision (and your body) then you are not interested and you'll go find someone else who does respect you. Be strong.
Stay by your decision for as long as you want/need to. If you eventually do want to have sex with this person, great! But don't do it just because he/she really wants it. YOU should really want it, too. Never have sex until YOU feel ready, willing, and excited about it. Don't settle. Wait until the desire is mutual, when you really, really want it. And then it'll be wonderful!
If you're finding that you never, ever want to have sex with this person, that's okay too. Maybe you're not ready to be sexual, or maybe this just isn't the right person for you. We've all been there; it's terribly awkward and uncomfortable, but it's a fact of life. If this is the case, you may want to get out of the relationship. Or if you're younger or have a low sex drive in general, just enjoy the relationship without sex. That's fine and healthy as long as you're both comfortable with it and you're on the same page. If the other person is not okay with this, then it's time to get out and find yourself a better match.
Above all, remember to love and respect yourself. These decisions are yours alone to make, despite what any partner might think. Take care of yourself and give yourself some credit. Don't feel guilty if you don't want to have sex! There is no shame in that whatsoever. Tell yourself, "I am a God/Goddess. I am beautiful and interesting and I am worth waiting for." It's true!