/jp/ - Otaku Culture

>>19639311
Read DOJG - page 50 - "Sound Symbolisms" (the book, not that neat table in the guide. you can find the book itself in guide's library)
It has a nice breakdown of common meanings that consonants and vowels give to those "onomatopoeias".

Example for words that you mentioned:
>ぐらぐら, ぶらぶら, だらだら or ぐるぐる.
"Liquid consonant [r] tends to represent fluidity smoothness or slipperiness"
That fits.

They are not all 100% right all the time, but knowing common ones will build up a feel for them and help to guess their meanings in context.

That book got few other neat articles and appendixes outside of main entries - it will be a good use of time to read them.