Getting through the game on Sith Master can be very frustrating at times. You'll have already gone through the game at least once in order to unlock Master (unless you used the SITHSPAWN cheat) so you should know what to expect on each level.
Unlike the first solution here, for me I found the best way to get through was to be patient and take my time. Use cover from blaster fire, your lightsaber on anyone who gets close, and use the force on distant enemies.
There's lots of guides for defeating Vader or the Emperor, so I'm going to list the places where I got stuck the most.
Also worth trying to save picking up jedi holocrons for when you're low on life, as they boost your life and force back to full.
When fighting bosses if you're able to knock them to the ground stand beside them and use the stab technique to take their life more rapidly.
TIE Fighter facility - the only real place I got stuck for a while was when you're sealed in by force field with a load of militia. Get in the middle section so the ones with baton's can't hit you, then use force grip to throw the guys with the authomatic guns into the force field. Once they're dead you can run around force pushing or using grip to throw the rest into the force field.
Raxus Prime 1 - be patient, electrocuting objects before throwing them causes a lot more damage. Also useful to pick up enemies and throw them into others.
Felucia 1 - if you get surrounded use repulse, otherwise use grip to pick up the closest enemy and throw him at the next enemy or off an edge where possible.
Empirical - The Purge troopers are the toughest opponents on this level, the first one I defeat by force pushing the door open, but not going through it. Use Push to kill the two stormtroopers, and lightning to take out the Purge trooper. In the last section stay on the walkway overhead and use repulse to knock enemies below, then use a mixture of lightning and push from above to wipe them all out. Keep moving so you don't get shot.
Cloud City - Use the grapple move on imperial guards to make short work of them. The load lifters are very annoying, try to deal with them one at a time, using the one you're fighting to block attacks from the other one. Always take out scout troopers (snipers) as a priority.
Kashyyyk - Activating lightning shield and then laying in to Purge troopers will knock them to the ground, you can then stab them repeatedly to kill them quickly. Don't do this when another one can see you or their rockets will kill you quick.
Imperial Felucia - try to take out rancors from a distance by throwing objects (especially exploding flowers) and using lightning. Maris is very annoying, but you can get her stuck in a corner and just repeatedly attack until she's dead.
Imperial Raxus Prime - Darth Maul is the hardest part by far, I hid behind a pillar, as he runs around to get you use repulse to fling him away. If he hits the wall and lands close use the stab technique, otherwise stay behind the pillar and repeat the repulse method.
When bringing down the star destroyer the most frustrating part is lining it up (I found), if you think you're almost there and the TIE's start shooting at you, don't keep pulling, get behind cover and pull again when it's safe. They will kill you very quickly otherwise.
Death Star - takes a lot of patience. Avoid fighting in the first part by running straight to the floor that you have to open and repulse so that you fall through.
The final section before Vader go straight down to the bottom and wipe out the 2 at-st's so you can activate the lifts. Take the lift all the way to the top, take out hover troopers and scout troopers in the middle (below). Then jump straight down to the observation platform. Sometimes purge troopers will shoot you with missiles, although not often. Fighting the 5 imperial guards, try to knock them over the edge using repulse, use grapple moves to keep moving about and knocking them down fast. Don't jump, their saber throws will knock you over the edge. There is a Sith holocron on the right and a jedi holocron on the left, use them to help you through the fight. Be patient, you probably won't do it on your first attempt.