A simple, yet workable answer to your question is to take the basic noun you are attempting to organize in the style of a continuum and simply add -er and -est (or the equivalent in correct spelling, such as -ier) to the root word.
heavy, heavier, heaviest
light, lighter, lightest
dark, darker, darkest
pretty, prettier, prettiest
and so forth. Another variation on the theme is to use "helping words" such as less, least, more, and most, as follows:
offensive, more offensive, most offensive
inoffensive, offensive, more offensive, most offensive
Using a "root" word and modifying it is only one way of indicating gradations, but it is the simplest, most straight forward, and perhaps least open to misinterpretation.
On the other hand, to stray from using a root word by attempting to describe gradations with words that have no root in common is to bring subjectivity into your description, which can be notoriously inaccurate and subject to conflicting interpretations, meanings, and connotations. For example,
large, massive, gigantic, gargantuan, King-Kong size, Empire-State-Building size, dwarf-star size, etc.
One can also add words (other than less, more, etc.) to intensify a characteristic, such as
snow white, shining white, brilliant white, dazzling white, blindingly white, whiter-than-snow white, etc.
Again, agreement as to how to arrange these descriptions in accurate gradations is difficult to come by.
Finally, a somewhat accurate way of indicating gradation is through the use of a questionnaire-type continuum from which you can derive, for example, an average number or score. For example,
On a scale of one to ten, circle the number that best describes your attitude about professional sports, with the number one being "couldn't possibly care any less" and the number ten being "couldn't possibly be any more enthusiastic."
Obviously, one could structure the continuum much more simply by assigning number one to "least enthusiastic" and the number ten to "most enthusiastic," with the numbers between one and ten being gradations of enthusiasm, with the amount of enthusiasm increasing with increasingly higher numbers (or conversely, the amount of enthusiasm decreasing with decreasingly lower numbers).