On any CTF server, your strategy will be dictated by the game situation, how many players are playing, and what their skill level is. On public servers, the number of people can change throughout the game, and skill levels can be highly varied, so you may have to change tactics mid-game to compensate.
It's generally best, if you have multiple useful people on your team, to split the players into offense and defense. The offensive players are responsible for stealing the enemy flag and bringing it back to the base. The defensive players are responsible for guarding the flag, and chasing down any enemy attacker who grabs it. This way, once the offensive player returns with the flag, they can simply wait on (or near) their flag stand until their flag is returned and immediately score. If there are multiple defensive players, it can also be extremely helpful to have some of them sit back at their base and wait for the offensive player to return with the flag and help keep them from dying to the enemy defense, as well as keeping any enemy offense from waiting around for the flag to be returned to immediately grab it again.
These positions are usually called offense (O), chase defense (chase), and base defense (base). Competitive CTF matches generally have 4 on 4 players, with two players on offense, one chase defense and one base defense per team.
But first, a quick note on speed. In Capture the Flag, speed makes a huge difference. A split second can be the difference between a cap and having to wait for your flag to be returned again. For this reason, all players in Capture the Flag will use whatever tactics they can to increase their speed. (There is an entire sub-section devoted to just this topic.) Since all players will be moving fast, your saber will be virtually useless as an assault weapon, since it is only helpful at close range. For this reason, guns are the weapon of choice for dealing out damage in CTF. The lightsaber is still invaluable though, as a shield. It is capable of blocking many types of weapon shots near-perfectly.