1. On Purim we are required to put on Tefillin. Even if someone already prayed he should keep his tefillin on until after completing the Megilla reading. This is based on the Talmud (Megilla 16b) explaining the verse To the Jews was light and happiness, gladness and preciousness. The sages explained that preciousness alludes to Tefillin. (See Mishna Berura 693, 6)
When a person reads “and preciousness” he should touch both his hand Tefillin and his head Tefillin and kiss his hand afterward. Those who wear Rabbeinu Tam Tefillin in addition to Rashi Tefillin and put the Rabbeinu Tam Tefillin on before Ashrei-Uva Letzion should do the same and wear their Rabbeinu Tam Tefillin when reading the Megilla. When reading “and preciousness” he should kiss his tefillin (as mentioned before).
2. The only addition to the amida is “Al’Hanisim” . We also do not say Tachanun on Purim.
The Power of Tefillin:
The tefillin contain four passages from the Torah. The tefillin of the hand includes all passages in one box, and the tefillin of the head contain the passages in four separate chambers. The tefillin of the head have a three-pronged shin engraved on one side and a four-pronged shin on the other. The way the straps are tied form the shape of the letters dalet and yud. Together they enwrap and connect a person to the holy Name of protection, Shadai.
The four head chambers contain the Torah passages corresponding to the four parts of the brain. When a person places them on the part of the head known as a baby’s “soft spot,” and ensures that they do not slip downward toward the forehead (but rather they remain at the hairline), he is placing them at the physical “gate” of the soul that rests within the brain. This allows the soul to connect to the eternal light, which infuses it with illumination. Conversely, the tefillin of the arm, which rest upon the bicep muscle angled toward the heart, transmit their light to the spirit that resides within the heart (the spirit is the source of emotion while the soul is the source of thought and logic). A person who wears tefillin every morning will be able to start his workday with a more illuminated soul and spirit. As a result, he will make fewer mistakes at work and will have an easier time overcoming resentments and other negative emotions. After all, the tefillin have done their job for the day.