Here is yet another particle you can use to list things. It also does other things, though. Listing, as you would imagine, is a case particle usage. After all, that's what と is in this case. And, this usage is specifically seen in between nominal phrases. Notice how the word "nominal" used instead of just "noun." This means that you can link things with や that are grammatically made nouns.
や lists things incompletely. This means that there is a sense that there are more related things implied. It may list nouns, phrases, and even clauses like "and", but it more so lists in categories.
1. ピクニックには、お菓子や飲み物を持って行った。
We brought candies, drinks, etc. to the picnic.
2. 家は電車やバスの停留場に近くてとても便利なところです。
My home is close to the stations, bus, train, etc., and it's (in) a very convenient place.
3. 牛や馬が草むらで草を食む。
Cows and horses graze in grassy places.
4. 東京や韓国へ行く時や、飛行機で行きます。
Whenever I go to Tokyo, Korea, etc., I go by plane.
5. 何やかや言っては両親にお金をせびる。
To say this and that to get money from one's parents.
Word Note: The か in the above expression is not the particle か. Rather, it can be written in 漢字 as 彼, the same character for "he" and actually has the same origin as かれ. Both are demonstrative words, and in this case, it is being used as an indefinite pronoun.
This classification of や happens to not be as important as the conjunctive usage, which is why more must be said of it. Attached to an adverb and accompanied with a statement of exclamation, it strengthens the meaning of the adverb that it is attached to. This is rather limited, so it is best that you only use this with set phrases and other instances that you see it used in. For instance, the first example has またもや, which happens to be a common set example of this.
6. またもや失敗しました。
I lost yet again.
7. 今や遅しと勝利を待ち侘びていた。
He was just impatiently tired of waiting for victory.
8. 彼の言葉に、祥子はまたもや目頭を熱くした。
His words made Sachiko yet again move to tears.
From 冷たい誘惑 by 乃南アサ.