At that point I'd probably pick out one of the list for special attention using "not only ... but":
There are several recommendations I have to further improve the sites, not only to improve their profit but to decrease their cost and improve their usability.
I'd cut that down further, though:
I have several recommendations to improve the sites—not only to improve their profit, but to decrease their cost and improve their usability.
On a song-by-song basis, this format is often used1:
Lyrics by Dean Eikmann, Music by Dorothy Page
or, if one person composed both:
Music & Lyrics by Theresa Jones
So, if your singer/songwriter is Dave Brown, you could use:
Music & Lyrics by Dave Brown
as the first heading, and
Music by Dave Brown
as the other. You could also add a third heading:
Performed by Dave Brown
in the case where he may have performed songs that were written and composed by others.
1Examples of this format can be found here and here. Moreover, this page list several songs in both formats, along with songs that were performed by another artist, such as: "The Way We Were" Lyrics by Alan Bergman & Marilyn Bergman, Music by Marvin Hamlisch, performed by Barbra Streisand.
Best Answer
'Clearly' is the word you need. It describes how you are advised to speak. 'Speak' is a verb, so you need an adverb to modify it. 'Clearly' is an adverb. ['Clear' is an adjective and is used to qualify a noun – but that's not what you're trying to do here.]
Having just given you the official grammatical story, I have to admit that adverbs are gradually going out of fashion, in the UK at least. There is a tendency to use the related adjective instead. But "Try to speak as clear as you can." still sounds wrong to me.
[One adverb that is almost never used these days is "regularly". People say "on a regular basis" instead. Similarly "on a daily basis" is used instead of just "daily". These strike me as weird circumlocutions; they always amuse me.]