There are several types of clues embedded in these puzzles.
This answer is deliberately slightly vague. Solving riddles is essentially a creative act of invention and as such can not be mechanised.
Let's walk through a few to illustrate:
Full poem:
You might try to pet me or kick my butt
but you can not touch me no matter what
If you gave me presents I'd leave you for sure
but take what's around me and I will endure
You can search the whole ocean or even beyond
in sometimes for sure, a loch or a pond
If you see whats behind it
you are very close
And as you assumed
its right under your nose
Now let's walk through it line by line:
You might try to pet me or kick my butt
but you can not touch me no matter what
A couple of options here. "Pet me" could refer to the letters of "me". However the second line indicates that are dealing with something intangible. So, let's constrain ourselves to concepts and things which "cannot be touched". Example candidate list: Darkness/Reflection/Truth/Nothingness/Sun.
If you gave me presents I'd leave you for sure
We could be dealing with present tense. "I'd leave you", could mean we are dealing with a word containing a "u" which when removing some letters (like "ID") would leave something else. Alternatively, more metaphorically, rather than symbol tricks, if you give/add something it is no longer what it was. The second option is closer to our feelings about the first clue. We can lean towards Nothingness now. However this is probably never going to go this smoothly but it is intuitive.
but take what's around me and I will endure
This really looks like a symbol trick. Like maybe the letter in the middle is an "I". It may also mean that so long as you don't mess with the core of the thing (which cannot be touched - clue #1), it will not be affected. It is hard to map this to anything on our preliminary list (darkness maybe?). Nothingness may also fit.
You can search the whole ocean or even beyond
This is very cryptic and confusing. It does not seem to reveal anything. But it gives the impression that the thing cannot be "found". But notice the trickery of the words spoken aloud taking different meaning. One must always keep an eye out for homophones - whole does indeed = "HOLE" - something to consider. Anagrams of ocean should also be considered.
in sometimes for sure, a loch or a pond
It is very unclear what a "loch or a pond" has to do with anything. Do take notice that the author is cunning and a German... "Loch" means "HOLE" in German...
If you see whats behind it you are very close
This just goes further than "cannot be touched". This is more like "is transparent". It may also mean to look "behind it" (the letter T). "You are very close" - probably means that if your candidate is transparent then you are looking good.
And as you assumed its right under your nose
This looks like a clever double meaning (I would expect it to have the following 2 meanings). It is implied that the answer is supposed to be obvious - a day-to-day thing. And that there is some relation to the physical body.
OK, so let's take stock... From our original candidate list "Nothingness" (include equivalent concepts like "Zero" (and thus "O")) is looking very strong and would probably get accepted due to inability to refute using the clues. But please do notice some possible hinting to a "HOLE". "Nothingness" is quite close to "HOLE", and "HOLE" fits just a tiny bit better (knowing the German connection helps a lot).
Let's go with HOLE!
Doing one that I made might be good because I know the intention entirely.
Full poem:
I'm lying down, with a dah-ditty-dah, in the middle of the end,
I'd hang upside-down similarly with my friend,
Were I to flip over, with a dah-ditty-dah, it'd be the middle of the day,
Right way up I cannot plainly say,
Here's the key, let's end the fun,
I'll tell you a secret, I hide behind one
What am I?
Now let's walk through the poem line by line.
I'm lying down, with a dah-ditty-dah, in the middle of the end,
This line relies on drawing suspicion to the words "dah-ditty-dah". Hopefully, one would notice that this is the vocal sound used in Morse code. "Middle of the end" will almost always be referring to the letter "N" (this is a clue of the first kind). So let's look at Morse code of "N". It is -.
. Supposedly it is "lying down".
I'd hang upside-down similarly with my friend,
"Similarly" here should mean "in the middle" or possible "lying down". You should try both - like branch the search. So, what's in the middle of "friend" - "i" and "e". We should move along with "a" ("e" upside-down). And even "!".
Were I to flip over, with a dah-ditty-dah, it'd be the middle of the day
Again "dah-ditty-dah" and "middle of the X". Let's look at A in Morse code. It is .-
. A clear pattern emerges. Let's start to solidify the conjecture of !
.
Right way up I cannot plainly say,
Ah-hah, one does not "say plainly" when using !
. However, "Right way 'up'" could refer to a letter trick giving 'pu'. So this clue could be of the first or the second kind.
Here's the key, let's end the fun,
"Here's the key" is quite attention grabbing. "What is the key!?" we ask. Indeed, it could be a literal key... how many types of those do we know and use? - a door key, and a keyboard key, a piano key. Well, we are conjecturing something like a symbol, so probably a keyboard key.
I'll tell you a secret, I hide behind one
"Tell you a secret" does not sound like a clue, but rather filler that signifies that a clue is coming. "I hide behind one" - this could refer to the letter "E" - this is almost a possible answer to the question. However, since we are think about a keyboard, let's try the key with 1 on it. We see that it also shares the !
.
Let's go with !
.