There is a rule: If you want to give an orgasm, you have to not focus on the orgasm. You have to focus your attention on the pleasure of the process of giving orgasm to the girl. This is the basic key. You have to be sure, that she is feeling good, she is enjoying sex with you and orgasm will come. Girl needs to be completely relaxed. She needs to trust you. No tension. She is your sexy lady. Maybe little massage before is a good starter. Remember, not every technique works on every girl. Every woman is a different. Communication is very important. You need to find out what she likes, if technique you are applying, makes her good. And as you are applying it, you have to fit rhythm, speed, strokes, etc to her needs. It doesnt mean, that you are more talking than having sex in the bed. There are also non verbal communicative methods, for example squeezing hands or body response. Be watchful. And dont forget to escalate your effort. Escalation is very important. Guys can come to orgasm very quickly, we got horny, we masturbate for awhile and we are done. Girls are little bit tricky, they need gradual and systematic escalation to come to orgasm. And with every stage of this escalation, intensity of the stimulation is increased. Very powerful and effective tool is teasing. It is not only about stimulation clitoris. Every girl has several very sensitive erogenous zones which are connected. Before you get to stimulation of the clitoris, you can rub her inner thighs, buttocks, etc... Do it slowly, you need to rise her sexual excitement. With gradually stimulation of inner thighs or buttocks, she got more horny. Her pussy will be wetter and wetter. Dont go into her pussy directly. You need to tease her. She will beg for it. As you are building up this anticipation in her, it will grow in you as well. But be aware of giving before receiving. Be sure that she receives sex pleasure fom you first. It is hard job, because when we got horny, we want to come out asap. You need to learn how to control your sexual desires, how to control yourself. It is not masturbation while you are watching your fav porn or sex video. This is real. Be gentle. Give her the best orgasm ever and you will see the difference. Try to compare blow job she gives to you before achieving orgasm with sucking your cock and giving you blow job after she got orgasm. It is a totally different story.