We don't have any real standards for writing votes. If you follow the general principle of including as much detail as possible, your vote will probably be very informative to a large audience. Enclosed herein are simply suggestions for people looking to write better votes.
The answer is an astounding "YES!". As long as you think you've used the product enough and have a good feel for it, you should vote. There's no need to be an "expert" as long as you say so in your review. Do you heed the expert's advice when it comes to movies? books? Many trust the advice of a friend or an acquaintance just as much!
To start your vote, identify the background from which you're coming from so that the audience knows how closely your vote applies to themselves. Are you an expert or just starting out? Do you use the product often? How long have you used it for? How long ago did you obtain it? Think of answering the questions of What? When? How? and Where?
Establish a short list of the good and bad aspects of the product. Including a list of both helps make your vote appear less biased and will earn your vote more respect.
Comparisons with other products require a little more experience, but are invaluable in establishing a reference. Readers who have had experiences with those other products will gain a much better understanding of your rating scale. For example, "My Buick is bad", sounds pretty negative. However, "My Buick is as bad as my Mercedes-Benz", isn't so bad anymore -- at least to those who think highly of a Mercedes-Benz.
To round out your vote, a short summary at the end should be used to re-enforce its main points.