Congratulations, you have went through the stereotypical section "do's and don'ts" and now you are ready to have more understanding of the mapper's rhythm and what to look for!
In this section we are mostly going to focus more on things that is helpful to notice upon modding a map as we dissect it.
(Disclaimer: this is my view on how to do things)
Differentiating rhythmatic problems and Rhythm suggestions
Modding out rhythmatic problems is rather difficult for a new modder as one of the toughest things to mod about these is not knowing what to actually look for and when seeing an issue within a map.
Is it problematic? Is it intentional? Is it a minor mistake? These are questions that always have to be ask upon making such mods which causes the new modder to feel rather overwhelmed.
So how would we go about these within a mapset? Well let me explain.
What is a major rhythm issue? What I considered a major rhythm issue is when the rhythm is either:
All over the place, following all sort of instruments, vocals, melody etc. and not being consistent with any of that at the same time.
Blatant inconsistency.
Obvious mistakes that more or less affects gameplay at a negative level.
Greatly overmapped whilst also ignoring stuff that is actually in the song (fairly common within new mapper's maps)
What is a minor rhythm issue?
Rhythm at times stop being consistent but unnoticeable at sight
Ignoring something within the song that could be mapped but not necessarily have to
Over-mapping that is used poorly but easily fixable within a few clicks
Even whilst thinking of it this way on differentiating major rhythm issues vs minor rhythm issues, I can very well see when problems could arise for each and every day modder since the biggest thing is: How do you notice rhythmic issues?
Finding rhythm issues/suggestions
Now, how to find rhythmatic issues within mapset. As a new modder it is very easy to look at say an experienced/semi-experienced mapper's mapset and not understand what exactly is it that you have to look out for within it, whilst new mapper's mapset, you likely will still struggle, but you are able to actually pinpoint the issues at hand if they are obvious enough at sight.
This is usually why a lot of new modders skipped around on experienced mapper's or simple mods that could be rather unhelpful for the mapper at hand (such as a nc mod without actual reasoning i.g)
So here how I would go about this:
Upon looking at a difficulty, look through it overall first
It is quite important to say the least since say for example you were modding a set with up to 3 choruses that is more or less the same with little variation.
If you only are modding just the first chorus, you may think to yourself "What rhythmatic problems could there possibly be, it is perfectly clean." and then, stop modding it entirely and not go further or get lost in your way throughout looking at the map.
Instead of having such a mindset, instead look at the overall mapset first. If you still struggle to find an issue then repeat the process one or 2 more times, you won't find the issues right away unless you check thoroughly.
Eventually you will notice the major/minor rhythm issues + have proof that upon looking through the sections, especially when 2 more is nearly identical, there is always a chance for the mapper to do a rhythm pattern differently rhythm wise than the previous time, even if it is more or less the same.
Example:
Section 1 pattern at 0:00 follows vocals - throughout the entire section
Section 2 pattern starts at 1:30 has an inconsistency, following vocals and instead follows instrumental instead - throughout the rest of the section continues to follow vocals
Now unless the section is following a special occurrence in the song that has not happen in the previous section, which makes the exception here, then what you have is a rhythmic inconsistency that should at least be pointed out.
After continuing this process for every mapset you look at from now on, eventually the issues that you see within a mapset becomes more easier to notice. Don't be disappointed in yourself if you still struggle on this.
That example and what I demonstrated above is one of the more easier ways to find rhythm issues but what about finding rhythmatic issues within the same section? How would a new modder be able to go through that and find an issue?
For Rhythmatic issues within the same section try to divide the music into 4 parts:
Instrumental - (Drum, Piano, etc. Depending on song)
Vocals (If there are some. If not then scratch this)
Melody
Background Instrumental (hi-hats, etc.)
Then after, also considered the section at hand as a whole
What is the intensity? Calm, up-beat, slow?
How dense does it sound? Is it continuous 1/4, is it mainly 1/2 spam, or a mix between 1/2 and 1/1?
What is the most obvious beat it is doing? Is it mainly Vocals? Is it mainly Instrumental? Mainly Piano or Drum?
Finally depending on the length of the song
What did the mapper follow in other sections? Mainly vocals, Mainly instrumental, Melody?
What makes this section so special? Does it do anything different from previous sections that justify having some patterns different from the rest? If so what?
Now with this established, this is a lot to consider but make sure to go through this one out of time especially if you are a new modder who is still being exposed to the modding scene.
As long as this method is being applied throughout your modding experience, it will become muscle memory at a certain point.