Is there any Brachah for putting on a טיכל or מטפחת (headscarf) - like when one puts on his tallit or like an act like washing ones hands? Same applies to a כיפה or יארמולקע. And if there are no Brachot for putting on these head-coverings, could someone explain to me why no Brachah is said?
Why we do not recite a berachah upon covering our heads with a kippah:
The Shulchan Aruch (2:6) seems to imply that the obligation of covering one’s head is only an obligation when reciting a berachah and not when walking around. However, see in Yabia Omer (9:1) who writes at length on this subject and concludes that nowadays it is indeed an obligation to walk around with a proper head covering. In any case, being that it is not an absolute obligation, it does not warrant a separate berachah.
The Shulchan Aruch (46:1) actually states that there is a berachah which is recited for wearing a Kippah, or wrapping our head, and it is the berachah of “Oter Yisrael b’tifarah.” The Bet Yosef explains that even though this berachah was originally meant for people who used to wear a turban or proper head covering, it is customary to nevertheless recite this berachah even for those who only wear a small head covering. He adds, that even according to the opinions that it is strictly speaking permitted to walk without a head covering, it is nevertheless a mitzvah for one who does so.
(With thanks to Rabbi Nacson).
As the question with regards to yarmulkes was very well answered by Levi I am only answering the question with regards to married women covering their hair which is obligated in the Torah as it says in Kesubos 72a:
ראשה פרוע דאורייתא היא דכתיב: ופרע את ראש האשה ותנא דבי רבי ישמעאל: אזהרה לבנות ישראל שלא יצאו בפרוע ראש
- Her hair revealed is prohibited from the Torah as it says with the Sotah that "her hair should be revealed." The house of Rabbi Yishmael teaches, this is a warning for Jewish (married) women not to go out with uncovered hair.
Does one make a Bracha when not breaking Shabbos or not showing any inappropriate parts of the body?
Is their a Bracha for fulfilling any of the 365 Lo taasehs (negative Mitzvos) or Lav haba michlal asei (negative Mitzvos inferred from a positive command) in the Torah?
The answer is no. This is because one is constantly obligated to refrain from doing an Aveira and has not "fulfilled" his obligation while not doing an aveira.
For example: there is no exemption of looking at an immodest woman while refraining from looking at a different immodest woman.
This is written explicitly in the Rashba: שו"ת הרשב"א ח"ג ס' רפג:.
מברכים רק על מה שבעשיית המצווה נפטר האדם מהחובה במצווה זו.
One makes a blessing only on the part of a Mitzva which by doing it one is exempt from fulfilling this particular Mitzva.