Before you give/receive a hug you must take into consideration the position in which your partner is engaging you. This is very important. Observe how the person is embracing you so that you may respond in the best way. There are 4 possible embraces:

Underhand:
Your partner approaches you with his/her arms ready to wrap around your torso, under yours. This type of embrace is commonly undertaken by those who are smaller than you, though this is not necessary. Respond to this embrace with an Overhand:

Overhand:
The person approaches you aiming over your shoulders. This is evident by a certain characteristic move which looks sort of like a "dive", though it does not always present itself like this. It is common for someone who is taller than you to approach you with this embrace. This type of embrace is hard to master, and I'd recommend you only use it to respond to an Underhand.

Cross (Right):
Your partner approaches you with his/her left arm higher than the right. This will result in your heads tilting to your right, and having each other at your respective lefts. Only with Cross-type hugs can the position of your head be determined by the approach, the prior two don't give any insight into this, they may end up on the left or right (it is not always, however, that the position of the head can be determined in these types of hugs, but most of the time). The left arm will come over the shoulder, while the right arm goes under: this applies to both of you. This embrace is the most common one, and usually performed by two people who are about the same height. It is also recommended, since you may both cover the most area with your arms and get a tighter, better fitting grip on each other. Use this same embrace as a response.

Cross (Left):
Your partner approaches you with his/her right arm higher than the left. Your heads will tilt to your left, and you will end up at each other's respective rights. The right arm will come over the shoulder, while the left arm goes under. Respond with this same embrace.

So you have come together; since your bodies should be neatly fit into each other, there are only two things you need to keep track of at this point: your head, and your arms/hands.

Your head:
Whether you have ended at each other's respective left or right, there are basically only two options for your head at this point: 1) Look forward, maintain your heads touching, and lay your chin on the person's neck lightly if you would like. 2) Burrow your head into your partner's neck, which conveniently seems to allow it to fit. This is most common between lovers. So please do not do this unless this is your partner! It is also common if you're being embraced while crying. Note that head positioning may be limited by the person who is hugging Overhand.

Your arms & hands:
This is where it gets tricky for most people. Depending on what type of embrace you have given and received, the maneuverability of your hands will be dictated. Once again, it is best to share a Cross-type hug, so that both your head and arms get the most out of it. Depending on which type of embrace you are sharing, your arms/hands will be positioned in several ways:

• With an Underhand embrace you may wrap your arms around the person's torso or lift them upwards so that they reach over your partner's shoulder. The latter is not recommended unless the hug is short and generally friendly; also, your hands would only be able to tap. If you wrap around the torso, you may lay one arm over the other, though it is better if you put one on top of the other (i.e.: from the back, "-" stacked arms, or "=" arms both on the back). You may rub with limited range and also pat.
  
• With an Overhand embrace your arms will typically wrap around the person's head, though you may manage to drive them into the upper torso with a certain angle. This gives you limited maneuverability: you may rub with a very limited range, and pat.
  
• In both Cross embraces, the arms and hands have the most freedom. Do not be afraid to touch the person's back: you're hugging, your partner will not be upset if you touch his/her back, in fact, (s)he will want you to. Do not lay your arms on top of each other, instead, cover some ground.
  
  

After you have embraced the person for a certain time, you may go on to move your arms and hands, and either "rub" or "pat". Rubbing consists of running your hands up and down his/her back, creating a very soothing sensation. Patting consists of just that: clapping your hands on his/her back softly. Take some time to take in the hug, however, before you rub or pat. It is actually not necessary to do either of these. Note that many people do not like pats, and many like rubs very much. You may now disengage and are complete with your hug. Ahh, breathe in all the air you were deprived of while your lungs were being squished. Great job!!!