There are no particular rules and laws either in foreplay or in intercourse. The only laws and rules are the ones reached by the lovers by mutual and often unspoken understanding. Whatever is pleasing and satisfying to both the husband and the wife is right and proper; and whatever is mutually displeasing is wrong. The only limitation to this general rule would be any Shariah rule which goes against the wishes of the husband or the wife.
A. Foreplay is Highly Recommended
Sex without foreplay has been equated to cruelty. The Prophet said, “Three people are cruel: …a person who has sex with his wife before foreplay.” 33
As for the role of a woman in sexual foreplay, the Imams have praised a wife who discards shyness when she is with her husband. Imam Muhammad al-Baqir (a.s.) says, “The best woman among you is the one who discards the armor of shyness when she undresses for her husband, and puts on the armor of shyness when she dresses up again.”  After all, modesty and chastity in public is the hallmark of a Muslim lady.
These sayings clearly show that the husband and the wife should feel completely free when they are engaged in mutual stimulation which is known as foreplay. There is nothing wrong, according to Islam, for a woman to be active and responsive during sex. As for the Islamic Shariah, all the mujtahids are unanimous in saying that the act of sexual foreplay in itself is mustahab (recommended). Likewise, it is recommended not to rush into sexual intercourse. The operative word is mutual pleasure and satisfaction.
B. Techniques of Foreplay
As far as the methods of mutual stimulation in foreplay are concerned, the Shariah allows the husband and the wife to see, kiss, touch, smell and stimulate any part of each other's body. Therefore, oral sex, as it is known, is allowed. Imam Musa al-Kazim (a.s.) was once asked, “Can a person kiss his wife's vagina?” The Imam said, “No problem.” 
The only restriction is that no foreign object should be used. The restriction on the use of foreign objects is based on the following hadith. 'Ubaydullah bin Zurarah says that he had an old neighbour who owned a young slave-girl. Because of his old age, he could not fully satisfy the young slave-girl during sexual intercourse. She would therefore ask him to place his fingers in her vagina as she liked it. The old man complied with her wishes even though he did not like this idea. So he requested 'Ubaydullah to ask Imam 'Ali ar-Reza (a.s.) about it. When 'Ubaydullah asked the Imam about it, the Imam said, “There is no problem as long as he uses any part of his own body upon her, but he should not use anything other than his body on her.” 37
Though masturbation (i.e., self-stimulation of one's own sexual organ till emission of semen or orgasm) is not allowed, in the case of married persons, there is no problem if the wife stimulates her husband's penis till the emission of semen or the husband stimulates his wife's vagina till orgasm. This is allowed because it does not come under “self-stimulation;” it is stimulation by a lawful partner.
C. Sexual Intercourse
Is there any particular position for sexual intercourse which is forbidden in Islam? No! As far as the basic coital positions are concerned, there are no restrictions. The term 'basic coital positions' denotes the positions known as the man above, face to face, woman above face to face; side position, face to face; rear-entry position in which the husband penetrates the vagina from the rear. Actually, the Shariah has left it on the husband and the wife to explore and experiment as they wish.
However, it is makruh to adopt a standing position, or to face the qiblah or keep it on the backside during the intercourse. It is advisable to refrain from the acrobatic positions given by some sexologists of the East and the West which might even cause physical harm. Remember, the basic rule is mutual pleasure and flexibility. If one partner does not like a particular position, then the other should yield to his or her feelings.
It is highly emphasized that at the commencement of intercourse the partners should recite Bismillaahir Rah'maanir Rah'eem (In the name of Allah the Beneficent, the Merciful).
D. Anal Intercourse
The opinions of our mujtahids vary on the permissibility of anal intercourse. The majority of the Shi'ah mujtahids have derived two conclusions: (1) that anal intercourse is not haraam but strongly disliked (karahatan shadidah) provided the wife agrees to it. (2) and if she does not agree to it, then all mujtahids say that it is precautionarily wajib to refrain from it.
However, during the last decade of his life, Ayatullah al-Khu'i departed from the majority view and gave the ruling that it was precautionarily wajib to abstain from anal intercourse no matter whether the wife agrees to it or not.
Maulana Sayyid Muhammad Rizvi says, “I would strongly advise against anal intercourse,” and quotes the saying of Imam Ja'far as-Sadiq and Imam 'Ali ar-Reza (a.s.) about anal intercourse: ”Woman is a means of your pleasure, therefore do not harm her.” 
After the intercourse the partners may first wipe their genitals with clean pieces of cloth. It is recommended that the same cloth/towel must not be used by both of them.
 Wasaelush Shia, vol. 14, p. 40
 Wasaelush Shia, vol. 14, p. 82
 Wasaelush Shia, vol. 14, p. 14-15
 Al-’Urwah, p. 625
 Wasaelush Shia, vol. 14, p. 77
 al-Khu’i, Minhaju ‘s-Salihiyn, vol. 1 (Beirut: 22nd edition) p. 64
 Wasaelush Shia, vol. 14, p. 101-102