When you are writing for someone else, it can be hard to know for sure what sort of style they are after in the writing they have asked for.

Some kind people may specify how they would like the piece to be written, but usually, it is up to the writer to interpret as they see fit.

Generally, a conversational style is easiest to read.

The average reader, even in first world countries, has a low level of reading skill, so break down your information and try to explain in simple, uncomplicated terms, without being condescending, of course!

Shorter articles are generally better if they are for the purpose of providing information, rather than just content fill.

The following link demonstrates an article that has been written in an easy to understand style. It is about a technical subject, but is still easy to comprehend.

You can impose your own personality in the piece quite easily if you are writing in a conversational style, and most webmasters will be happy with work written in this way.