What were some Jewish customs?

Answer 1

The following examples are customs, not laws.

Language:
In many cases, Jewish communities created their own languages that were based on the local language but quite different from it. These include Yiddish, Ladino, Judeo-Arabic, and others.
Speech:
Jewish speech (in any language), especially among religious communities, is seasoned with hundreds of expressions that refer to various Torah-concepts.
Instead of saying "Tomorrow I'll visit," the phrase will be "Tomorrow I'll visit im yirtzeh Hashem" (God willing). See also: An extensive Jewish glossary of words
Cuisine:
Jewish communities have created certain foods in keeping with Torah-requirements. Matzoh-ball soup and matzoh-brei on Passover replace any leavened equivalent. Gefilte fish (which contains no bones) was created to avoid the stricture against separating bones from food on the Shabbat.

Answer 2

The following examples are customs, not laws.

• Language:
  

In many cases, Jewish communities created their own languages that were based on the local language but quite different from it. These include Yiddish, Ladino, Judeo-Arabic, and others.

• Speech:
  

Jewish speech (in any language), especially among religious communities, is seasoned with hundreds of expressions that refer to various Torah-concepts.

Instead of saying "Tomorrow I'll visit," the phrase will be "Tomorrow I'll visit im yirtzeh Hashem" (God willing).

Link: An extensive Jewish glossary of words

• Cuisine:
  

Jewish communities have created certain foods in keeping with Torah-requirements. Matzoh-ball soup and matzoh-brei on Passover replace any leavened equivalent. Gefilte fish (which contains no bones) was created to avoid the stricture against separating bones from food on the Shabbat.

Link: Shabbat and Festivals

• Home design:
  

Here in Israel, homes in religious neighborhoods tend to be designed with two sinks in the kitchen, an additional sink for handwashing outside the bathroom, and a porch for the sukkah.

• Charity:
  

At every Jewish religious wedding, and in very many synagogues, you'll encounter people collecting alms for the indigent. Every religious home has at least one pushke (charity-box) which, when filled, is donated to the tzedakah (charity) of one's choice.

I've tried to give examples that are not in themselves obligatory, but reflect Torah-commands or attitudes.

See also the other Related Link.

Link: More about Jewish life