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Since even before our last lesson on the particle も, there have been two important usages of it discussed with other grammar points. As such, before looking at usages we haven't gone over before, we'll look back at these two usages with the knowledge we've gained since the second lesson on も!

・The Use of も in ～ても・でも

It goes without saying that the meaning of the particle も falls within the same definitions that we have learned thus far even when it's used with the particle て. The particle て, whether it remains in this form or is voiced as で, becomes paired with も to mean "even if." 

1.  考えても、全然答えがわかりません。
I have no idea what the answer is even if I think about it. 

2.  自分でも気付かないうちに抜いてしまったり、やめなければいけないと思ってもやめられなくなったりするといいます。毛髪などは抜いても再生しますが、長期間繰り返すことで髪が生えにくくなることもあります。
(They) say you pull (your hair) out when you yourself don't even realize it and become unable to stop even when you are aware that you need to stop. The hair may grow back even when you pull it out, but there are times when it becomes harder for the hair to grow (back) after repeatedly (pulling it out) over a long period of time. 
From NHK. 

3.  家族にやめるよう注意されても、やめることが出来ない。
I can't stop even when I'm warned to stop by my family.

でも has four possible interpretations. ① It can be the voiced form of ～ても when certain 五段 verbs are used (ex. 泳ぐ + ～ても ＝ 泳いでも). ② Used with the て form of the copula, it follows nouns to mean "even" in both positive and negative contexts. The noun can either be a subject or an object depending on the verb of the clause. ③ When seen in ～でもない after nouns/adjectival nouns, it still translates as "even" or "neither/nor" depending on whether it is used more than once in the sentence. ④ それでも is a conjunction meaning "even so," but when shortened to でも, it means "but" and is used just like the English equivalent in sentence initial position.

4. お茶でもしませんか？
How we have some tea?

5. でも、確かに向こう岸まで泳いでも行けそうな距離だな。
But, it really does seem like the distance is doable even if I were to swim to the other side. 

6. 私は現金信奉者でも暗号資産信奉者でもない。
I am neither a proponent of cash nor a proponent of crypto-assets. 

[Go over use in interrogatives]

In Lesson 88, we learned how the particle も attaches to all of the basic interrogatives in Japanese to add the meaning of "all." Whether the context is an affirmative (肯定文) or negative sentence (否定文), も expressions that everything is within the specified scope. 

7.  野菜は体にいい、と誰もがそう思っているだろう。

Everybody probably thinks that "vegetables are good for you." 

8. 何もかもが嫌になった。

Anything and everything has become unpleasant (to me). 

Grammar Note: As demonstrate in Exs. 7 and 8, interrogative expressions formed with も can often be used as nouns, which is why the subject marker が can be seen after も.  

Grammar Note: 何もかも means "anything and everything" and is a great example of the XもYも in the affirmative. The か in this expression can be spelled as 彼 and is actually a こそあど itself which refers to an indefinite entity, a.k.a, "any." 

9. 誰もいないのにインターホンが勝手に鳴る・・・
My intercom rings by itself even though nobody is there. 

10. いつものようにログインしてください。
Please login like always. 

11. どこも閉まっている。
Everywhere is closed. 

12. 中国へ一度も行ったことがありません。
I have never gone to China even once. 

13. たいしたご馳走もございませんが、どうぞ召し上がって下さい。
This is by no means anything special, but please help yourself to it. (In reference to food one is presenting)

Grammar Note: Although not an example of も within an interrogative expression, Ex. 13 illustrates how the negative sense of "all" (none) is the same as expressing lack, which we learned about in the second lesson. It's just that with interrogatives, there will be specific corresponding translations in English to keep in mind. In other words, "even who" makes no sense, but "everyone/nobody"  do. 

We also saw how the particle でも, which is a product of も, adds the meaning of "any."

14. いつでも連絡してね。
Reach me at anytime. 

15. それならどこでも買えるよ。
If you('re talking about) that, you can buy it anywhere.

Grammar Note: Here, どこでも can be simply interpreted as どこで + も.

The grammar point "Xが／もXならYもYだ" is used when the speaker wishes to show commonality between two coexisting scenarios which both deviate from what one would anticipate. The critique made is usually negative, but what determines whether the criticism is positive or negative is the overall context.

16. 値段も値段なら、味も味。所詮は、カップ麺だな。

With price being the price, the flavor is the flavor (one would expect). Ultimately, it's (what you'd expect of) cup noodles. 
Critique: As the speaker clarifies, you get what you pay for as far as flavor goes. 

17. 値段も値段なら、味も味！カップ麺とは思えないくらい美味しかった。

If price is the 'price', then 'flavor' is 'flavor'! It was so delicious one could hardly believe it was cup noodles. 

Critique: Ex. 16 would be what most people would expect as common sense, but the change in intonation alone indicates that the relationship between X and Y is not reliant on each other. "Price" and "flavor" can coexist. 

18. 親が親なら子も子だ。
If parents are parents (as such), then a child is a child (as such).
Critique: What can you expect of a children with parents like that?

19. 教師が教師なら、生徒も生徒である。
If the teacher is (supposed to be the teacher), then the students are (just that:) the students. 

If a student isn't doing great, look at the teacher. If a child is acting up, perhaps their upbringing provided for by the parents isn't so great. The relationship between X and Y in these sentences is so strong that one could easily paraphrase the sentences to be far more direct. 

20. 親を見れば、子どもがわかる。
You can understand the child if you look at the parent.

21. 教師を見れば、生徒がわかる。
You can figure out the students by looking at the teacher.

If the relationship between X and Y is not mutually reliant as is the case between "parent and child," "teacher and student," or "you get what you pay for" like in Ex.16,  the critique expressed by  "Xが／もXならYもYだ" pertains to how X and Y coincide, and its their coexistence that brings about your critique. 

22. 自民も自民なら、野党も野党だ。
If the LDP is going to be the LDP, then the opposition parties are going to be the opposition parties.  
Critique: If the Liberal Democratic Party is what it is, then the opposition parties are going to act no differently. Neither side is working towards solutions if they only act as expected. 

23. 犬も犬なら猫も猫だ。
If dogs are dogs, then cats are cats.
Critique: If the dogs you're worried about are just being dogs, then the cats around you behaving 'poorly' as cats is just as big of a problem to worry about. 

As for when the particle が can be used as opposed to も, the sentence must be one in which X and Y are mutually reliant. が becomes more ungrammatical the more subjective the scenario is. Mutually reliant relationships can be objectified, but two things that happen to coexist (problematically or not) is a subjective matter. The particle も's ultimate role is to inform the listener that Y is also like X, and this inclusion makes sense in both objective and subjective contexts. The particle が, on the other hand, singles out X initially but then the speaker brings up Y as being intrinsically part of the dilemma.