42. Strictly speaking. Although we practice some aveilus during sefira, we do not really find in the words of the poskim an issur to wear new clothing or make a Shehecheyanu during sefira. It is more lenient than the aveilus observed during the Three Weeks. Thus, strictly speaking, one may wear new clothing during sefira (מאמר מרדכי סק''ב, ליקוטי מהרי''ח מנהגי ימי העומר, הליכות אבן ישראל עמ' רי''ד ועוד ).
43. Prevalent minhag. Nevertheless, the prevalent minhag is to be machmir not to wear new, nice garments that bring joy and are not frequently bought or that one generally makes Shehecheyanu on, e.g., a suit, a new Shabbos garment, a new hat, a new sheitel, etc. (יוסף אומץ סי' תתמ''ה, לקט יושר עמ' צ''ז, שו''ת בצל החכמה ח''ד סי' מ''ח, שו''ת מהר''י שטייף סוף סי' רמ''ט ) An exception would be if there is a big need for it, e.g., one’s suit ripped or is very shabby and he is embarrassed to wear it or the like.
44. However, there is no reason not to get during sefira new, regular garments that do not bring joy and are bought regularly, e.g., a shirt, underclothes, shoes, glasses, a shell, or weekday children’s clothing.
45. Buying clothes. Since we say Shehecheyanu today when we wear new clothes, not when we buy new clothes, there is no problem with buying clothes during sefira (כף החיים סי' תקנ''א סקפ''ח ).
46. Shehecheyanu. If one chances upon a new fruit or garment that requires a bracha of Shehecheyanu, he may make the bracha of Shehecheyanu (מ''ב סק''ב ).
47. Chosson, bar mitzva. A chosson or bar mitzva boy may wear new clothing for the simcha. He is considered someone who does not have other clothing, as it is not befitting for him to wear his old clothing. If he can wear them new for Shabbos, that is preferable (אוצר הלכות סי' תצ''ג אות כ''א ).
