Typically, Rogues are not strong characters in boss fights, as opposed to Mages and Warriors. However, quite a bit of experiences has led me to belive that one of the best strategies for Rogues to fight bosses is to have a lot of Habits and Dailies and check them regularly. This way, you can do a ton of damage to the boss, even without special boss-damaging skills. I have done over 25 or even 30 damage to bosses by clicking on positive Habits regularly and completing all of my Dailies.
Dailies[]
Try to create Dailies that you can easily do most days. This way, you will take less damage from bosses and deal less damage to party members . Also, rest in the Inn if you are out for a day or two. This will also prevent damage and potentially death .
Habits[]
Having only positive Habits helps you avoid damage, but can be slightly less motivating. If you want to also have negative Habits, boss quests can be an added incentive for you to avoid them in real life. Also, try to have a lot of positive Habits; this will make up for your lack of boss-damaging skills.
Summary[]
In general, try to check off Habits and Dailies as much as possible and have a lot of both.