Post: #1

So my house mates friend is coming over for a few days. She was here before and I know she likes me (told my house mate)..

I wanna make this a sure smash.

How to secure?

Post: #2

Can you isolate her? That's really what it will come down to if she's coming to your apartment. Half the battle is won since you didn't have to actively game her and get her to my apartment.

Post: #3

That might be kinda hard if my house mate is around.
I could try coming home a little late and if she is about to sleep tell her to come to my room.

Post: #4

Drop some fuckbait, ie: joint, come watch this video yada, yada.

Post: #5

Bold and smooth is the general formula for picking a girl out in a social environment like that.

LongDongSilver said it best—the fuckbait is key. What I would do is make sure you're lounging around the living room or other common room when she shows up and, since you make it sound like there's going to be a few people around, socialize with them when she arrives. Put yourself in the general conversation. Then, after a while, steer the focus to her and start talking to her directly. Neg her a bit, as much as you're comfortable doing, and from there build a conversation and drop a bit of bait.

From there, I would probably make plans to do something with her later to "catch up" (such as watch her favorite movie in your room, etc.). If she's into you, this is all more or less just guiding a train along the tracks of the FuckStation Expressway. Just give a plausible way that you can isolate later. At that point, you escalate.

That's the simple solution, and it really shouldn't be that complicated. But that's from the little I know about your situation. What exactly is the set-up of where you live? Is it a big house with lots of common areas? How many house mates (and, more importantly, which genders)? Do you have a roommate or your own room? What's the dynamic like between your housemate and the friend? How much free time do you have while she's around to work her?

There's are critical questions really.