Disadvantages are fairly fundamental to GURPS. They're amongst the very first things added to Man-to-Man - the first ones showed up in Roleplayer #1. Some of them have hardly changed since then.
How I deal with them in my games is pretty much out of the book, but with some caveats and explanations and clarifications.
Flow Naturally from Play
Your disadvantages should naturally flow from how you play your characters and determines that flow smoothly and naturally.
You want to pick disadvantages that either have set effects you can live with (even thrive with, because they're fun) or have roleplaying consequences you'd like to roleplay out. They shouldn't be forced. And they should fit how you perceive that guy acting in the situations you find yourself in.
You shouldn't need to refresh your memory every session of what's wrong with your guy.
As the GM, I shouldn't have to, either. If I look at your sheet and think, "Oh yeah, I forgot he's Curious" than you're not really being Curious.
Corollary: You should not have to tell anyone. "I run up and push the button because I'm Impulsive!" and "I'm stabbing that wounded guy again because I've got Bloodlust" and "I'm Stubborn, so I disagree. You guys should use Fast-Talk on me!" are really . . . moment-breaking. It's like an actor saying, "Hey, I'm angry because I'm an actor playing an angry guy!" Just play it, we'll know. Apologize during break for your character, doing in play is kind of lame and basically says, [Ralph Wiggum]"I'm Roleplaying!"[/Ralph Wiggum]. It also implies to the other players not to roleplay in a way that blocks you, even if their character would logically do that.
Self-Control as the Exception, not the Rule
The way I see it, if whenever your disadvantages come up in play you think, "I should make a self-control roll to avoid this" or "maybe it doesn't apply in this case," those disadvantages really don't fit your and/or your character.
Of course, there should be times when you really need to exercise some self-restraint and hold back from expressing your disadvantages. It's just an issue when those times are all times. If you read Bad Temper (12) as "On a 12 or less I'm not Bad Tempered," you're not really playing disadvantages the way I'm expecting as a GM. Even more so if you're reading it as "If I can't explain why I shouldn't even need a roll, then I get a 12 or less roll to resist." Being Bad Tempered should be your normal thing, even if you mostly restrain it when it really matters.
Greedy characters should go after money. Overconfident characters should be less willing to accept a situation is beyond them. Gluttons should eat a lot. Compulsive Carousers should be jumping into parties. Guys with Bloodlust should be putting in that extra shot to make sure someone is dead even if the players would prefer prisoners and prefer you not waste that combat turn. And so on.
Self-control rolls are for "I see serious consequences and need to avoid them" not "I see consequences and I need to avoid them." Even then, there should be times you don't want to roll, even if the other players at the table would like you to.
And if you feel this way about your disadvantages, they're really not the ones for you even if they sound right on paper. "My guy gets really mad! Except when it's not convenient, then his iron self-control kicks in." Okay, take a Quirk-level version and just be mad when it's convenient.
Tomorrow: Choosing and Mitigating your disads in my games.