Some omit the morning blessing of SheAsah li kol tzarchi. Therefore one would not be able to 'prepare' clothing that they only want to wear during the week by wearing them on Shabbos. Some permit music at a meal for a Pidyon HaBen during the three weeks.
On the 17th of Tammuz only eating and drinking are prohibited, unlike on Tisha B'Av which also prohibits washing, anointing, wearing leather shoes, and having marital relations. If Tishah B'Av should occur on Saturday night, an abbreviated havdalah (the b'rakhah over fire) is recited following the Kaddish Shalem in Ma'ariv. Whoever does work on Tisha B'av [to the extent that his mind is diverted from the mourning] will not see blessing from that work. Likewise, one may sing a lullaby to help drift a baby to sleep. One may cut nails during the three weeks, up until the week of Tisha B'av. Other Poskim however rule it is forbidden to smell spices on Tisha B'av. One should not purchase a new talit gadol as this would require making a Shehecheyanu. A mourner who is sitting shivah may go to the synagogue both evening and morning. For this same reason, one should not walk around in groups on Tisha B'av. Nitei Gavriel Bein Hamitzarim pg. On Shabbos and Yom Tov it is permitted according to all to serve all the available dishes. They are especially willing to permit a radio playing Jewish music for the purpose of kiruv. Other Poskim rule one may not recite Shehechiyanu even on Shabbos of the three weeks. Both opinions are quoted in Shulchan Aruch 551:16.
One who cannot eat milk products: One who cannot eat milk products may eat chicken [or a dish which contained meat. ] In any case, one should consult a competent rabbi. For Sephardim it's permitted to take a haircut during the three weeks even a Sephardic Yeshiva Bachur in a Ashkenazi Yeshiva [46] however, it's preferable to be strict not to cut the entire three weeks. Clothing that one is wearing is not considered a valid interval for this matter. When Maariv is not delayed, one should bring their Kinnot and their Eicha to the synagogue before Shabbat. Torah reading follows Tachanun (Shemot 31:11-14; 34:1-9). Haircuts and Shaving. Some say this space should be made opposite the entrance of the house, in order so that when one enters through the main door, he will immediately see the unpainted area and remember the destruction. If, however, wine is not being served and one does not commonly hear music, it is permitted. Adding Aneinu and ViNachem: Sephardim - the Chazzan adds Aneinu as a blessing in itself between Go'el and Refanenu, and Nachem in Boneh Yerushalayim at Shacharit and Mincha.
Singing on Your own. If wine fell into a food the food may be eaten if it contains sixty times the wine. It is the custom of the Ashkenazim and some of the Sephardim to sanctify the moon on Motzei Tisha B'Av. Sh"t Kapei Aharon 52 writes that it's clearly forbidden to listen to music during the three weeks. The fast of Gedaliah, the tenth of Tevet, Ta'anit Esther, and the 17th of Tammuz all begin at dawn and end when the stars appear. Leaving out one dish by a meal: - The Sages enacted that in commemoration for the destruction, upon making a meal for guests [or any other meal, including even a Seudas Mitzvah] one is required to leave out from the table one of the commonly served dishes of food. Haircut: - One may not cut hair throughout the three weeks. We do not shave or get haircuts. Rav Schachter supports this comparison from Sh"t Panim Meirot 3:37e, and goes so far as to question Sh"t Igrot Moshe Y"D 2:137 who compares the week of Tisha BeAv to Aveilut of Shiva. Iggerot Moshe YD 1:224 and Aruch Hashulchan 551:31. Even then it is permitted for a woman before immersion, or for a man as well, in honor of the Shabbat (for example if Tisha B'Av is on Shabbat and postponed to Sunday, or if it is on Sunday itself). Nevertheless, despite the above ruling, some Poskim rule that even on a Taanis Nidche the Baal Bris is to fast the entire day as usual, and so is the custom of certain communities. One who forgot to say Nachem should say it after Aneinu in Shema Koleinu. If fasting is dangerous to your health, you are forbidden to fast.
All clothing which are permitted to be laundered during the nine days, as explained in Halacha 8, are likewise permitted to be worn in their freshly laundered state. Fasting on the 17th of Tammuz stems from the voluntary consent of the people. Mikraei Kodesh 5:1 quoting the Masa Chaim of Rav Chaim Palagi that the rabbis of his generation established that people shouldn't go on trips during the three weeks. It is customary not to say the blessing of She'hechiyanu during the Three Weeks. However, one may prepare clothes ahead of time by wearing the clean clothes for about half an hour, and doing this multiple times until he has enough clothes until Tisha B'Av is over.
One may eat without any restrictions up until sunset. Igros Moshe E. H. 4:84. Doing so is a proper custom, as the three weeks is a time of severities, and this mourning benefits the soul tremendously. Rav Moshe Feinstein quoted in Moadei Yeshurun page 129:11, Rav Elyashiv quoted in Avnei Yushfei 1:113, Sh"t Mishna Halachot 6:109, Chazon Ovadia Taaniot page 153. Mishna Brurah 551:81 and Shaar Hatziyun 551:91 as well as the Chayei Adam 133:18 conclude that children even below 6 should not get haircuts and bring two reasons from the Terumat Hadeshen 142.
When washing hands in the morning and after using the bathroom, one should wash only up to the point where the fingers connect to the palm. If one forgot to say Ata Chonantanu, he does not need to repeat Shemoneh Esrei, as in any event he will not be eating until he makes Havdala over wine on Sunday night. Likewise, one who is weak is not required to be stringent in this matter and may hence sleep on his bed as usual. 16] There is also a minhag not to wear new clothing that don't require a Shehecheyanu specifically during the Nine Days. Sh"t Igrot Moshe 1:168, and 3:100.
Gentile workers: One may not hire gentile workers to build a building for pleasure or beauty purposes during the nine days. The same holds true for the Nine Days when we all mourn the destruction of the Batei Mikdash. Igrot Moshe 4:112(2) writes for great need one can be lenient to cut one's hair the night of Shiva Asar BeTamuz. Instead one can wear them for the first time on Shabbos and 'break them in' that way. The Talmud writes that one who mourns the destroyed Jerusalem will merit to see it rebuilt. This Gemara is brought as Halacha by the Rambam (Taaniot 5:6). Say Shehecheyanu (except for Shabbat). The custom is to refrain from taking a haircut, including the beard. The women are likewise accustomed not to weave the warp during the nine days. Sanhedrin page 104b. The Poskim rule that one may not eat more than usual prior to a fast as this defeats the entire purpose of feeling oppression on that day. This applies likewise to children.