The idea conveyed by the suffixes called “augmentatives” does not always have to do with an increase in size or intensity. In fact, it is rarely that their meaning is purely augmentative. Generally, they’re more often derogatory, as in ‘palabrota' (filthy word), ‘amigote’ (bad influence or undesirable friend), segundón (subordinate or second in line).
In other instances, they’re attenuating: 'parecidón' is ‘more or less alike’ or ‘somewhat alike’; ‘terriblón’ is ‘a little mischievous’.
Also, it has a ponderative sense or a sense of extolment. The suffix –azo has specialised in this: ‘relojazo’ (excellent watch), ‘chocolatazo’ (exquisite chocolate), and so on. This is just one among the diverse functions this suffix performs.
And, in many cases, the value of these endings is diminutive; it was thus that ‘ratón’ originally stemmed from ‘rata’; ‘islote’ from ‘isla’; ‘cordón’ from ‘cuerda’, all conveying the idea of a small size. This way, if anybody were to insist upon that each type of suffix has a unique and unchangeable value, we would find paradoxical or contradictory formations such as the use of–ón in pelón (‘hairless’), where the suffix has acquired a diminutive value to the point where it denotes total absence of the substance.
Although it is quite true that, as mentioned aforehand, these suffixes can be incorporated into any kind of word, for adjectives, the true augmentative ending is «-ísimo, -a», this is what is called a «superlative» in grammar.
In multiple cases, one or more extra sounds are inserted between the root of the word and the augmentative suffix. It is generally the –z, for modified words that end in an –e, or specific diphthongs or certain consonants.
suave → suavezón (attenuating);
media → mediezota;
collar → collarzote;
cien (noun, as highest grade) → cienzazo (ponderative).
We can also observe many sui generis cases:
rico → ricachón
bueno → bonachón
voz → vozarrón
nube → nubarrón
grande → grandulón.
casa → caserón
What these consonants in each specific case depend upon for their selection, is a highly-unpredictable issue; they must be learned as an already-formed entity, together with the inventory of nouns and adjectives belonging to the language.
In all Spanish dialects, the use of augmentatives is much less frequent than that of the “diminutives”, possibly due to psychological reasons or to euphony (pleasant sonority).