Rockets and missiles are best used when at mid-range, around 150-200m. Be aware that all rockets have a safety range where they will not detonate. If your target gets too close to you, you will not be able to hit.
{{EPtip|info=Iceflares and Starflares are the exception, where their safety proximity is 0, however you will find this is ineffective for people to use, as it usually ends with them doing more damage to themselves, because of splash damage.}}
Rail guns are best used at long range and are a defensive weapon. Stay as far back as possible, make your enemy come to you, and remember that you are capable of scoring a hit on your target anywhere under 1000m. But, I'm not going to give away all the secrets of rail combat, you'll have to find those on your own.