There are many approaches to handling FTL and almost all of them break the principles of conservation of mass and energy. Unfortunately, without them things can get very boring in a solar system without some very clever GM handling. So we have FTL. That doesn't mean we're allowed to do it wrong. Some things to consider with FTL - how fast is faster than light, and can you look out the window and see much of space. We have explored multiple forms of FTL already in our setting:
Transdimensional FTL - the "fastest" way to get where you need to go, this is a strain on the engines, and extremely costly in energy. But it gets you where you're aiming for almost instantly. This form of FTL relies on a space-pinching principle - for a moment the dimensions of space are overlapped and the ship transits from one set of points to another. Little to no time passes between, but you better have your math right or you'll land in the wrong place - or worst inside of something else. Planets win this fight every time. Momentum is conserved on the other side, which is to say: Speedy thing goes in speedy thing comes out. The distance you can pinch is directly related to the power available in the engines - there is a range.
Compression FTL - the "slowest" of the FTL methods, this relies on the same principles as electrons jumping from one state of excitation to another. In essence while the compression drive is running, space is wrinkled up in microscopic - electron sized - amounts allowing the ship itself to make the same sort of instantaneous jump that an electron does. It is definitely slower than Transdimentional hops as there is a briefest of resting point between the jumps, but the movement is easier on the engines and easier on the fuel. Unfortunately, it does require a direct transit - so make sure the course plotted accounts for the movement of galaxy and rotation of planets before you arrive. Running into something at high speed is less dangerous than appearing in the middle of it - but still distinctly unpleasant.
Jump drive FTL - This is a Gargorian technology - middle of the road system. While operating under the same space-pinching techniques as transdimensional FTL the biggest difference is the concentration and focus of power source. Jump drive relies on relatively close proximity of a gravity well to assist in the space-pinching. The range of the pinch is related to the strength and focus of the gravity well. A well formed singularity is your best source, but has it's own risks on approach. This is also true for suns, planets and the like. Leaping away from a gravity well is relatively safe. Leaping into one runs it's own risks.
Note: The crystals within the Trans-Dimensional Light Drive and Compression Drive are cooled and recharged by high alkaline sea water.
In general: At FTL speeds you are literally going faster than light. It is impossible to be shot at by lasers as you will outpace them, and certainly you are immune to more ballistic weapons such as torpedoes. Looking outside the window there will be absolute darkness - as there are no light particles able to keep up in order to illuminate a view. Thankfully, while pinching you are, in essence skipping the space between so the 'personal time' spent in transition is so miniscule as to be imperceptible. While under the effects of a compression drive - all of the above apply save for the effects of well - running into something while transitioning from jump to jump. There is a certain high degree of acceleration your ship much already be under before the compression can occur, and at each 'jump', your ship's momentum is maintained. Speedy things hitting still things tend to hurt one or the other or both.
Navigating in FTL - You have to have a map, or have mapped it out the 'slow way'. After all, one of three things will happen if you're pinching blind: 95% of the time you'll find yourself in empty space and nothing is there and it's boring and quite likely too far away from any fuel source for you to recharge your battery and make it home before you stave. 4% of the time you'll find yourself inside or merged with something unpleasant: planet, sun, galactic core, asteroid, other ship... 1% of the time you'll find something interesting *and* not be so close to it as to injure yourself. So while you *could* do a blind jump randomly to the limits of your pinch - but I wouldn't recommend it unless you were in that dire a situation. Note: mapping out the next target can be done with a good telescope and time to read an analyze your next star location. The same need for a good map applies to compression drives as well. At FTL speeds you're effectively charging blindly ahead - and running into something at high speed is still unpleasant.
All other engines operate under standard Newtonian physics.
Solar Drive - Regular Travel within Solar Systems. Most ships have a Primary and two secondary Solar Drives.
Thrusters - Normally combat thrusters, that allow quick maneuverability within combat. Or minor adjustments of the ship while in a higher drive form.
Jack Rabbit Thrusters - A Kalvania modification that allows the ship extreme combat maneuverability.