When writing most anything, objective is produce copy that is easy to read. This is particularly true on Web, because chances are majority of your visitors and newsletter readers are in hurry-up mode. They'll pass on anything that seems hard to read. Here are ways you can improve readability of your work.
1) The simplest word available is best choice.
Mark Twain often got paid by word. He once commented he preferred city over metropolis. Sure, "joke" is that he got paid for either word, and that city is quicker and easier to write. But he also knew it made his work easier to read.
2) Avoid using adverbs and adjectives.
"This is very hard to do."
"This is awfully hard to do."
"This is hard to do."
Which of above do you feel is best? I've asked a loaded question here, for "best" doesn't really apply. To strengthen your work, minimize use of qualifiers. There is simply no question here. The last form is strongest.
The point? Adverbs such as "very" and "awfully" often weaken, rather than strengthen. In previous sentence I was forced to use "often," for without it sentence is not true. That is, adverbs and adjectives do not always mess things up. But they often or usually do.
Alternatively, consider breaking flow. Then hit hard. For above, try:
"This is an awesome task."
This is a stronger claim than, "This is hard to do." Which is best depends upon way you want to make your point and who you want to make it to.
3) Keep sentences as short as possible.
Above, "This is hard to do," is also better choice, for it's shorter. Here's a sentence I wrote for another purpose. (I'll refer below to this as the, "Original.")
"Subheadings must flow from headline, revealing major benefits so that at end of page, reader has a good feel for content, even when only headlines are scanned."
It's much, much to long. 34 words. While it's not hard to read, it does slow reading because length makes it more difficult to follow. Personally, I try to hold to under 15 words, and less whenever possible. Even though it's longer (45 words), following revision is easier to read.
Revision #1: "Subheadings should flow from headline. Each should reveal a major benefit to reader. And at end of page, you want reader to have a good feel for content. This matters because most only scan headlines and subheadings."
4) Seek brevity and eliminate unnecessary words.
Revision #2: "Subheadings flow from headline. Each reveals a major benefit to reader. Collectively they need to describe page content. This matters because often only subheadings are scanned."