I'm a level 67 paladin... Who does not know how to tank.

[Vaer]

Look at the small bars next to the job icons in the party list - that's the threat meter. It shows the enmity list for your current target. If they are overtaking you use more enmity abilities. The idea is to make sure you always have the largest amount, when you get into optimization you want to have the highest amount by a slight bit and just use DPS combos instead and keeping yourself at the top as the fight goes on and balancing it. If you are just getting comfortable you can give yourself a large lead, most people in dungeons won't care. The weak combo (I'm guessing you're talking about Halone) that increases enmity is actually really high enmity. It has a multiplier attached to it so even if it does weak damage it generates a lot of enmity. You want to use this at the beginning to build a lead and then manage it after that.

Flash x2 is sometimes not enough without some other stuff if you have DPS that know what they are doing depending on their gear and yours.

Usually what I do for a trash pack is I'll lob the first mob, flash them when they get to me, use circle of scorn. I'll fast blade the mob that got lobbed, switch to another mob, savage blade, and halone the last mob. I distribute the combo to put some enmity on each mob so I don't lose them immediately depending on which mob the DPS decide to hit. Then i'll check the enmity list and use more flashes as necessary and pop a small cooldown like Rampart. If i'm double pulling i'll pop a bigger defensive cd and start using total eclipse when the hate is ok.

For bosses, lob, spirits within, halone combo x1-2, Scorn somewhere in there. After that Sword oath, flight or fight and dps combos if I think the healer can handle it. Else just dps in shield, keeping track of the enmity throughout the fight.

If you get a straggler you can use Provoke and lob/flash to get it back. This sometimes happens if DPS decide to hit things before you get situated or regens are on you. Ultimatum works as well (it is actually around you so you have to position properly) if someone pulls more than one mob off of you due to AoE, just flash them afterwards.