The Berachos
Before blowing the shofar, two berachos are said: Lishmoa Kol Shofar and Shehecheyanu.
When blowing for a man, ideally the listener should make the berachos. If he cannot do so, you can make the berachos (having in mind to be motzi him). You can do so even if you have already been yotzei the mitzvah.
When blowing for a woman, she should make the berachos. If she cannot do so (and you are not being yotzei the mitzvah at present), blow without berachos.
If blowing for a group, one man should make the berachos and be motzi everyone else. However, if the group consists solely of women, each one should make the berachos.
If the one making the berachos spoke between the berachos and the blowing, the berachos must be repeated (unless the interruption was related to the blowing).
Tekiah
Each tekiah must be at least as long as the minimum length of the middle blasts of that section. In other words, in the section of tashrat, each tekiah must be at least as long as 18 short blasts; and in the sections of tashat and tarat, each tekiah must be at least as long as 9 short blasts.
Shevarim
Each one of the three shevarim should be at least as long as 3 short blasts, and no longer than 9. Extra care should be given to the third shever, which some have a tendency to blow shorter than the rest.
If even a single teruah was added after the shevarim of tashat, you must return to the beginning of that unit. Therefore, if adding a short blast after the shevarim (as some are accustomed to do), make sure it is longer than the size of a teruah.
Teruah
The teruah is comprised of at least 9 short blasts. Some have a tendency to blow the last blast a bit longer than the rest; care should be taken that it is equally short.
Additional Halachos
The shofar should be held in the right hand, and should be blown using the right side of the mouth.
Take a breath between each tekiah, shevarim, and teruah. However, when blowing the tekios after krias hatorah—and similarly for mivtza shofar—do not take a breath between the shevarim and teruah of tashrat. Similarly, do not take a breath in the middle of an individual blast.
Both the one blowing and the one listening should not speak until the blasts are completed. If the one blowing spoke in between blasts (i.e., between a tekiah, shevarim, and/or teruah), there is no need to repeat them; however, if the one listening spoke during the blowing, those blasts must be repeated.
If the shofar blower is having difficulty proceeding, he may be replaced by another. The second person should continue from where the first person left off, and does not need to repeat the berachos.
If you cannot blow all thirty blasts (for example, if you do not have enough strength to do so or if the other person is in a rush), blow tashrat three times without a berachah.
The shofar may be blown after shekiah until tzeis hakochavim. However, no berachah should be made at that point.
