Never go overboard with your Character. Don't give him every ability imaginable and don't make him preternaturally alert and accurate. All people have flaws, including Starfleet Officers, and in my experience it's usually those flaws that set us apart from everybody else. We're here to have fun, so give your Characters depth and colour, not shallow perfection and invulnerability.

Also, always work within the Starfleet framework. You don't get to torture a prisoner, that's a quick way to a court martial for your Character and an abbreviated tour of duty. You don't get to blow things to hell with Tetryon pulse launchers unless another war breaks out or you get sent on a mission that's guaranteed to need heavy firepower. Whilst it's pretty to look at weapons like that and it makes you look big and heavy to walk around armed like a tank you won't be carrying that Photon Mortar on your Promenade patrol.

There are literally hundreds of books out there, quite possibly even thousands that claim to be Star Trek, but are usually heavily outdated or inaccurate and use weapons and technology that have never even been hinted at in Canon, so just because you've read it in a book does not mean that you get to play Wolverine as a Security Officer. I'll be the first to admit that there are a stable of authors out there who write some absolutely brilliant works that do nothing short of enrich our knowledge of Trek technology and methodology, but bear in mind that most of what you read is Fan Fiction and doesn't go down well with the other members of the club when you try and use it.

Stick to Canon and the STF Reference Manual wherever possible. This isn't to say that you can't create your own technology. We're all for new designs and new specs for weapons, species and technologies, but ensure that you get them approved for use before you start, particularly with Weapons and Technology (which should be critiqued and approved by the Engineering Department/Research and Development Department).

Above all else, before you lock and load, be aware of what ship you are stepping aboard. If you're looking to blow those alien scum to hell then you should be leaning more towards the larger classes such as Maverick and Pendragon that are more combat oriented. If you're looking for a rewarding time that will give you massive character development opportunities then head towards the Viking and Genesis class vessels. Personally, given the choice, I'd rather play a Science vessel any day because it gives you the opportunity to create characters of such rich history and realism that if you do finally take that step to the darker side of combat classes' people will find it a true pleasure to interact with you.